The Forestry Forum

General Forestry => Chainsaws => Topic started by: HolmenTree on April 15, 2020, 12:19:07 PM

Title: HolmenTree bikesaw projects.
Post by: HolmenTree on April 15, 2020, 12:19:07 PM
Been away for a while, thought I'd check in with some pictures of my project that's been keeping me busy.
I thought Ed (ehp) would especially like this!

This is my little 1982 YZ125 which at the moment I'm building the oil tank to match up to the fuel tank. It's got a peaky 202°/129.55° road race porting so I figure the 14T .404 sprocket will be lots enough of gearing.
Then it's on to adding the bar pad with Stihl 084 studs.

Last pic is my 1983 Honda CR250R waiting in the sidelines to get worked on.

(https://forestryforum.com/gallery/albums/userpics/21589/20200415_104904.jpg?easyrotate_cache=1586967288)
 
(https://forestryforum.com/gallery/albums/userpics/21589/20200126_152027.jpg?easyrotate_cache=1586967520)
 



Title: Re: HolmenTree bikesaw projects.
Post by: Evanguy on April 15, 2020, 12:33:22 PM
Thats awesome, i have a 1984 cr250 motor im building a saw with. I built it up quite a bit, When it was in my bike it dynoed at 46whp. Yours looks like a 84 without the big power valve box by the exhaust port. Well not really a power valve but a little flap that opens a small chamber in the head to make a low pressure zone at low rpms.  Either way i removed it on mine.

If you use an oringed head you can use a 3mm over piston from the 250r three wheel motor ( same part number but not listed under cr250)  if you dont oring the head you need to find a multy layer steel headgasket like on the newer motors, (  composite with steel ring wont seal) boyesen radvalve also picked up good power. Also switching to an '88 cr250 flat face carb was nice (38mm pj) i ported it some, (mostly cleaned up the castings and raised exaust port), used an oem 2002 cr250 pipe on it with no silencer

I didnt cut the transmission off like you did. I stripped it of all its bearing, gears and shafts then used the 2 rear mounts to attach my handle too. My top tandle is attached to the cylinder head mount.

I was thinking about building a newer cr80 next ( 20hp in stock form and revs to 12k)
Title: Re: HolmenTree bikesaw projects.
Post by: Hilltop366 on April 15, 2020, 01:09:45 PM
Cool projects guys, back in my bike dealer days I had a Yamaha rz350 for a while (twin cylinder 350cc two stroke) I always wondered how it would work as a race saw engine. I think the Banshee motor is very similar with out the YPVS.

Anyway the bike was super fun to ride and then I sold it so it matters not.
Title: Re: HolmenTree bikesaw projects.
Post by: HolmenTree on April 15, 2020, 01:22:37 PM
Evan, awesome to hear of your '84 250. Your cylinder head is almost identical to my '83. The plug leans in opposite directions with both years.

I looked at the '84 250 but the exhaust port with no bridge kind of scared me off a bit.
I may in the future put in a wiseco 69mm 526 piston but I'd need to lower my cylinder 3mm for it to work.
I got a 68mm cylinder and a spare 66.75mm cylinder both in excellent condition.
The reason I picked the '83 CR250R is it matches my right hand ignition YZ125  with the PTO opposite your '84
I can do both builds with the same laid down horizontal design and reversed engine rotation with a bi directional PVL ignition.

Title: Re: HolmenTree bikesaw projects.
Post by: HolmenTree on April 15, 2020, 01:24:57 PM
Cool projects guys, back in my bike dealer days I had a Yamaha rz350 for a while (twin cylinder 350cc two stroke) I always wondered how it would work as a race saw engine. I think the Banshee motor is very similar with out the YPVS.

Anyway the bike was super fun to ride and then I sold it so it matters not.
Those are strong motors alright.
But rules and regulations at the contests are standard with 1 cylinder only to keep things safe.
Honda CR500 is a wicked saw.
Title: Re: HolmenTree bikesaw projects.
Post by: Hilltop366 on April 15, 2020, 01:30:40 PM
Honds CR500 is a wicked saw.


Yikes! It must it needs a large pulley on the pull chord?
Title: Re: HolmenTree bikesaw projects.
Post by: lxskllr on April 15, 2020, 01:49:13 PM
Still on for May(is it?) Willard?
Title: Re: HolmenTree bikesaw projects.
Post by: HolmenTree on April 15, 2020, 02:43:25 PM
Still on for May(is it?) Willard?
Unfortunately I hear all shows  everything cancelled.
So next year maybe??
Oh well this time off will give my lots of time to get them built right and tested in the wood.
Couldn't find a better excuse to spend more time in the shop haha!
Title: Re: HolmenTree bikesaw projects.
Post by: barbender on April 15, 2020, 02:56:11 PM
Those things are just madness! I can't imagine a CR500 saw, those things were uncontrollable in a bike!
Title: Re: HolmenTree bikesaw projects.
Post by: HolmenTree on April 15, 2020, 03:03:17 PM
Thats awesome, i have a 1984 cr250 motor im building a saw with. I built it up quite a bit, When it was in my bike it dynoed at 46whp. Yours looks like a 84 without the big power valve box by the exhaust port. Well not really a power valve but a little flap that opens a small chamber in the head to make a low pressure zone at low rpms.  Either way i removed it on mine.

If you use an oringed head you can use a 3mm over piston from the 250r three wheel motor ( same part number but not listed under cr250)  if you dont oring the head you need to find a multy layer steel headgasket like on the newer motors, (  composite with steel ring wont seal) boyesen radvalve also picked up good power. Also switching to an '88 cr250 flat face carb was nice (38mm pj) i ported it some, (mostly cleaned up the castings and raised exaust port), used an oem 2002 cr250 pipe on it with no silencer

I didnt cut the transmission off like you did. I stripped it of all its bearing, gears and shafts then used the 2 rear mounts to attach my handle too. My top tandle is attached to the cylinder head mount.

I was thinking about building a newer cr80 next ( 20hp in stock form and revs to 12k)
Evanguy, thanks for the tip about the cylinder head. I noticed lots of glue on my one cylinder deck where someone was trying to seal it down.
I haven't run my Ebay pieced motor yet and I noticed the squish band in the head is off center as my picture shows. Both cylinders have the same offset with the head.
So I got to send it away with 3 pieces of squished solder to get it machined to normal. Will have to cut the cylinder top deck clearance in the hole to zero first.
I may make my own head gasket out of some copper sheet which is easily available through a local retailer in different thicknesses.
Our cylinder heads are strong with their 7 stud design.  Only the 1983 and '84 CR250R had a 7 stud head.
Has to be strong as the CR500 has a 7 stud head.

(https://forestryforum.com/gallery/albums/userpics/21589/20200208_133148.jpg?easyrotate_cache=1586977329)
 
(https://forestryforum.com/gallery/albums/userpics/21589/20191211_140050_28129.jpg?easyrotate_cache=1586977367)
Title: Re: HolmenTree bikesaw projects.
Post by: HolmenTree on April 15, 2020, 03:06:31 PM
Those things are just madness! I can't imagine a CR500 saw, those things were uncontrollable in a bike!
Yep they are a real powerhouse alright.
I never saw anybody handle a CR500 hotsaw in anything smaller then a one cut hot start 27 inch diameter Douglas fir.
Title: Re: HolmenTree bikesaw projects.
Post by: ehp on April 15, 2020, 08:18:00 PM
I hope you guys all got chain for those saws as no more high tooth being made is the word we re hearing , none has been made sense last June so hope you know someone with a roll or 2 .
Title: Re: HolmenTree bikesaw projects.
Post by: HolmenTree on April 15, 2020, 11:37:06 PM
I hope you guys all got chain for those saws as no more high tooth being made is the word we re hearing , none has been made sense last June so hope you know someone with a roll or 2 .
Still some new HT for sale but expect to pay $500 plus for s loop.
One guy was asking CAD$1000 for a loop for a 28" bar, Lol.
I was talking to a rep in Virginia Beach last fall and he says the factory is not replacing the worn out dies.
But there "may" be a new .404 chain in the works in the very near future.
I got 30 feet of NOS Oregon 50AL .404 to run on the YZ125's 20" b/c.
May run it for now on the Honda too.
Title: Re: HolmenTree bikesaw projects.
Post by: Air Lad on April 16, 2020, 03:35:53 AM
I owned a YZ125. C model around a 75 build I think
Yammy were first with monoshock system. That is suspension talk, nothing to do with cutting wood.
You're water cooled version is a country mile ahead of the old peaky, non user friendly power band thingy that I thought was the best thing since
sliced bread. Looks like yours has reeds .A later version had a valve that added low down torque and was controlled in unison with the throttle. Bike I had then was a trail only. About 89 model but the mx bikes might have had this valve mabye 85 ish. Dunno .
Hope she cuts great
Title: Re: HolmenTree bikesaw projects.
Post by: HolmenTree on April 16, 2020, 08:28:50 AM
My 1982 YZ125 here was the second year of water cooling and the first year for the powervalve.
Japanese MX motorcycle development really turned on with the biggest changes from about 1981 to 1986. Then after that it was just yearly small improvements.

Honda pretty well got most things right from day one in the 1980's and the other big three  (Yamaha, Suzuki, Kawasaki) manufacturers followed.  
But Honda did back track to some of their early designs.
Interesting note the Honda CR250R had the same 72mm stroke since 1978. Yamaha YZ250 ran a square 68mm×68mm B/S right up to the late 1990s then switched to Honda's 66.40×72mm B/S.
The big four shared alot of the same exact engine parts like bearings etc.


Title: Re: HolmenTree bikesaw projects.
Post by: barbender on April 16, 2020, 10:06:45 AM
Holman, how do you deal with the water cooling with no cooling system? Just fill the jacket with coolant since it won't run long?
Title: Re: HolmenTree bikesaw projects.
Post by: HolmenTree on April 16, 2020, 01:30:06 PM
Holman, how do you deal with the water cooling with no cooling system? Just fill the jacket with coolant since it won't run long?
No coolant needed. I filled up the cylinder's water jacket with Devcon aluminium epoxy. Keeps the cylinder bore more stable after increased horse power mods reducing distortion.
In competition we're allowed a minute to warm the saw's motor up.
Then on the word "go" we start the saw and makes our cuts as short as 3 to 4 seconds at WOT.
No water cooling needed, a quick efficient warm up is needed in this situation.
Heat  gauges help keep an eye on engine heat. Usually above 160F these engines will start to lose power.
Title: Re: HolmenTree bikesaw projects.
Post by: Evanguy on April 16, 2020, 03:53:09 PM
Thanks for making this thread, it got me re-excited about my build and I've since found all my parts and got back into it (sorry if im out of line talking about my build in your thread and posting pics, do let me know if i shouldn't be)

that's an interesting idea about cutting the case, then tipping the motor back and reversing the direction, saving on both wright and over all size. also getting the exhaust out of the way of the bar/cut zone. your building technique is quite a bit advanced then mine. i like it. 

the 84 exhaust port sure is big but i haven't found an the issue with it, the one time i did have an issue is on my first rebuild i did on the bike i didn't have the FSM and the exhaust port has a bulletin about how to chanfer the exhaust port to not catch rings on it. interestingly i have cylinder jugs that has the recall done on them and also one that haven't (pics attached) 

going 3mm over was fun for sure but lead to a load of headaches with pushing coolant before i realized why, i copper sheet would have been the simplest i was young at the time and didn't think about that. i ended up cutting an o-ring grove around the combustion chamber then using gasket maker to seal the coolant part. i do like the 7 stud design, lots of clamping force evenly spread.

i wasnt sure what i was going to do with the coolant, that's a good idea really. i see I'm going to learn a lot from this thread.

i had no idea about the chain and have never even looked into what i needed, i assumed id be running the same type of 404 chain that's on my stihl 084

i wonder if an 83 head would bolt on the 84 bottom since i'm not using the ATAC system, i guess i can just buy a cheap base gasket and that will let me know, or if you ever are feeling board maybe you can grab the measurements on the 4 base studs


(https://forestryforum.com/gallery/albums/userpics/59944/20200416_101827.jpg?easyrotate_cache=1587066039)


(https://forestryforum.com/gallery/albums/userpics/59944/20200416_101746.jpg?easyrotate_cache=1587066067)


(https://forestryforum.com/gallery/albums/userpics/59944/20200416_101800.jpg?easyrotate_cache=1587066103)


(https://forestryforum.com/gallery/albums/userpics/59944/20200416_101812.jpg?easyrotate_cache=1587066139)


(https://forestryforum.com/gallery/albums/userpics/59944/20200416_101955.jpg?easyrotate_cache=1587066182)


(https://forestryforum.com/gallery/albums/userpics/59944/20200416_164757.jpg?easyrotate_cache=1587066492)


(https://forestryforum.com/gallery/albums/userpics/59944/20200416_164801.jpg?easyrotate_cache=1587066484)

Title: Re: HolmenTree bikesaw projects.
Post by: ehp on April 16, 2020, 09:28:05 PM
if you want to cut fast you need the taller tooth and the bigger the wood the higher tooth makes a bigger difference. if your cutting small wood 3/8 chain will cut fast on the 125, I would not put it on the 250
Title: Re: HolmenTree bikesaw projects.
Post by: ehp on April 16, 2020, 09:31:23 PM
I put my bar oil in where the coolant went in the jug
Title: Re: HolmenTree bikesaw projects.
Post by: Evanguy on April 16, 2020, 09:41:14 PM
^^ I was thinking about doing that..then using the drain plug to put a petcock on and use a gravity system, if i wasnt going to make a coolant system on it. I may go that route still.
Title: Re: HolmenTree bikesaw projects.
Post by: HolmenTree on April 16, 2020, 09:58:42 PM
if you want to cut fast you need the taller tooth and the bigger the wood the higher tooth makes a bigger difference. if your cutting small wood 3/8 chain will cut fast on the 125, I would not put it on the 250
I'm no longer running 3/8 on the 125.
Both the 250 and 125 are setup with .404.
Biggest wood I'll cut will be 22" pine in Kaslo B.C and 22" dug fir in Squamish.
They got a 140cc hotsaw class and open hotsaw class in Squamish where I can run both saws.
The 125 will run 12T .404 and the 250 will run 14T .404 but possibly 16T if I get the power I'm expecting it should put out.
I'll  be keeping a look out for some 46RST but this 50AL chain I have is nice .050 .404 chain on both saws.
Lots of room for race chain mods with that big chassis.

(https://forestryforum.com/gallery/albums/userpics/21589/20180722_202943.jpg?easyrotate_cache=1533416165)
 
(https://forestryforum.com/gallery/albums/userpics/21589/20140127_155032.jpg?easyrotate_cache=1390859952)
Title: Re: HolmenTree bikesaw projects.
Post by: HolmenTree on April 16, 2020, 10:33:05 PM
Thanks for making this thread, it got me re-excited about my build and I've since found all my parts and got back into it (sorry if im out of line talking about my build in your thread and posting pics, do let me know if i shouldn't be)

that's an interesting idea about cutting the case, then tipping the motor back and reversing the direction, saving on both wright and over all size. also getting the exhaust out of the way of the bar/cut zone. your building technique is quite a bit advanced then mine. i like it.

the 84 exhaust port sure is big but i haven't found an the issue with it, the one time i did have an issue is on my first rebuild i did on the bike i didn't have the FSM and the exhaust port has a bulletin about how to chanfer the exhaust port to not catch rings on it. interestingly i have cylinder jugs that has the recall done on them and also one that haven't (pics attached)

going 3mm over was fun for sure but lead to a load of headaches with pushing coolant before i realized why, i copper sheet would have been the simplest i was young at the time and didn't think about that. i ended up cutting an o-ring grove around the combustion chamber then using gasket maker to seal the coolant part. i do like the 7 stud design, lots of clamping force evenly spread.

i wasnt sure what i was going to do with the coolant, that's a good idea really. i see I'm going to learn a lot from this thread.

i had no idea about the chain and have never even looked into what i needed, i assumed id be running the same type of 404 chain that's on my stihl 084

i wonder if an 83 head would bolt on the 84 bottom since i'm not using the ATAC system, i guess i can just buy a cheap base gasket and that will let me know, or if you ever are feeling board maybe you can grab the measurements on the 4 base studs


(https://forestryforum.com/gallery/albums/userpics/59944/20200416_101827.jpg?easyrotate_cache=1587066039)


(https://forestryforum.com/gallery/albums/userpics/59944/20200416_101746.jpg?easyrotate_cache=1587066067)


(https://forestryforum.com/gallery/albums/userpics/59944/20200416_101800.jpg?easyrotate_cache=1587066103)


(https://forestryforum.com/gallery/albums/userpics/59944/20200416_101812.jpg?easyrotate_cache=1587066139)


(https://forestryforum.com/gallery/albums/userpics/59944/20200416_101955.jpg?easyrotate_cache=1587066182)


(https://forestryforum.com/gallery/albums/userpics/59944/20200416_164757.jpg?easyrotate_cache=1587066492)


(https://forestryforum.com/gallery/albums/userpics/59944/20200416_164801.jpg?easyrotate_cache=1587066484)

Evanguy you can post pictures  all you want.
Your '84 is a good motor like the newer '85 '86. The only thing it shares with my '83 is the head.
Only reason I went '83 CR250R is it has the PTO on the left side just like my '82 YZ125.  So I can build then both the same .
When I finish the 125 I'll be ready to do a good job on the 250.
With these saws they have:
•Excellent lower center of gravity.
•Can cut from both sides of the log 
•Excellent view of the log and b/c.
•Left hand is not up high holding saw.
•Fuel tank is not over the exhaust pipe
•Ignition coil, oil tank and fuel lines covered up out of the way under one cover.
•These saws oilers are pressurized with a valve connected to the throttle to squirt oil at 3/4 throttle.
I had that oiler setup on the YZ125 for over 36 years.

Title: Re: HolmenTree bikesaw projects.
Post by: HolmenTree on April 16, 2020, 11:07:26 PM
Evanguy,
Here's a picture I drew up last year of my '83 base stud spacing and crank.
I was trying to see if a newer CR250 cylinder and crank would fit. 
They don't. 

(https://forestryforum.com/gallery/albums/userpics/21589/20191111_143218_28129.jpg?easyrotate_cache=1587092834)
 
Title: Re: HolmenTree bikesaw projects.
Post by: ehp on April 17, 2020, 06:47:37 AM
in 22 inch wood without high tooth I donot care how much power you have you will not be even close , one thing you need to think about is your port timing , motor is shut off and you start it on go , if your porting is to high the motor will not spool up in time so the race is already over before you even touch the wood , . Having lots of power for the 3rd cut is way to late
Title: Re: HolmenTree bikesaw projects.
Post by: ehp on April 17, 2020, 06:51:26 AM
Oregon harvester chain the new stuff is far better than the chain you have as far as cutting speed goes, the tooth is taller , yes its .063 gauge but your chain is .058 gauge up at the top so only .005 bigger plus the .063 is far stronger
Title: Re: HolmenTree bikesaw projects.
Post by: HolmenTree on April 17, 2020, 08:19:01 AM
in 22 inch wood without high tooth I donot care how much power you have you will not be even close , one thing you need to think about is your port timing , motor is shut off and you start it on go , if your porting is to high the motor will not spool up in time so the race is already over before you even touch the wood , . Having lots of power for the 3rd cut is way to late
All good advice Ed, but even though my YZ125 has the exhaust at 202° it's still a hyper quick 50mm stroke 125cc engine. It's VForce 3 reed cage and TRX style custom drag pipe will have her at WOT into the first cut.
My CR250R port timing will be at 190°/129° also with a VF3 reed cage and drag pipe.
Title: Re: HolmenTree bikesaw projects.
Post by: HolmenTree on April 17, 2020, 08:31:48 AM
Oregon harvester chain the new stuff is far better than the chain you have as far as cutting speed goes, the tooth is taller , yes its .063 gauge but your chain is .058 gauge up at the top so only .005 bigger plus the .063 is far stronger
Are you sure that harvester chain isn't. 080 gauge?
I don't think there's enough sideplate on a semi chisel harvester chain to make it into a proper square chisel.
Matter of fact I see some shows are banning harvester chain because of it's high chain shot forces going through safety shields.
The 46RST HT is not such a big deal, guys like Mel Lentz complain it stretches bad, weak and depth gauges too low. 
I'm not shy to put 40 hours into my 50AL race chain. With the matched sprocket gearing for the competition's diameter of log, I'll have it under control.  :)
Title: Re: HolmenTree bikesaw projects.
Post by: ehp on April 17, 2020, 12:12:05 PM
there is different depth gauges setting on high tooth, All your fast times are cut using high tooth or 1/2 inch . the chain fills under the cutter and once the tooth is full it cuts no more wood , Believe me we tested a lot and high tooth on 3 cuts in 20 inch is over a second faster and closer to 2 seconds. I have some taller tooth .063 Oregon here we tried from harvester . Its ok up to about 12 inch wood , anything bigger the higher tooth takes over . You geared down pretty good to , A stock 250 will scream a 16 tooth gear using high tooth chain . High tooth is stock stihl chain with just a taller tooth , some guys pull the tooth off and use .080 gauge setup and the harvest chain is chisel not semi , It pays to know people lol, I spent lots of time in Oregon plant here on making my own high tooth chain . Only problem was the plant was booked for at least 2 but more likely 3 years making chain
Title: Re: HolmenTree bikesaw projects.
Post by: ehp on April 17, 2020, 12:18:19 PM
well then you should know , the bigger the diameter of log the higher number of tooth the gear needs to be so the cutter cuts the full way across the block . If your cutter gets full it stakes the rest of the way across the block and starts bouncing in the cut . The chain your using we played lots with and went as high as 24 tooth gear on a rotax and after 20 tooth it made zero difference as was still a lot slower than high tooth setup running a 16 or 17 tooth setup
Title: Re: HolmenTree bikesaw projects.
Post by: HolmenTree on April 17, 2020, 04:41:39 PM
Ed, yeah I missed out on the Stihl HT chain. Could have easily bought some loops a few years ago from J.S.B. Called him last fall and he said their gone.
Jerry Gingras set a record with the 46RST. 404 years back beating his 1/2 inch times.
The chain has been around for almost 20 years now. Hopefully the rumor it'll be replaced with a newer version...as long as there still is a Stihl Timbersports.

I was in the Guelph plant on a tour back in the early 1980's. Lots of history in that place.
It used to be Planer Chain Ltd Guelph, Ontario Canada.
Oregon bought Planer out in 1952.
1957 the company changed its name to Omark Industries but still keeping the Oregon brand name.

Here's some pics of the Stihl 46RST high tooth.

(https://forestryforum.com/gallery/albums/userpics/21589/facebook_156915911335428129.jpg?easyrotate_cache=1587155802)
 
(https://forestryforum.com/gallery/albums/userpics/21589/404ht.jpg?easyrotate_cache=1587155910)
 
Title: Re: HolmenTree bikesaw projects.
Post by: snowstorm on April 17, 2020, 04:42:52 PM
Most harvester chain is 404.  80 Stihl make 2 versions. 1 is stronger. Oregon 18 or 19 x
Title: Re: HolmenTree bikesaw projects.
Post by: HolmenTree on April 17, 2020, 04:53:27 PM
Most harvester chain is 404.  80 Stihl make 2 versions. 1 is stronger. Oregon 18 or 19 x
The last .063 harvester chain I ran on my Stihl 090-60" was the older Stihl chain . I thought everything went .080 every since.
I got a 12T .404  NOS Sandvik .063 harvester sprocket to run on my YZ125 and ordered a 14 also. The hub adapter is getting made at the moment. 

(https://forestryforum.com/gallery/albums/userpics/21589/20191202_130346.jpg?easyrotate_cache=1587156765)
 
(https://forestryforum.com/gallery/albums/userpics/21589/20191204_100348.jpg?easyrotate_cache=1587156761)
 
(https://forestryforum.com/gallery/albums/userpics/21589/20191204_100337.jpg?easyrotate_cache=1587156760)
Title: Re: HolmenTree bikesaw projects.
Post by: HolmenTree on April 17, 2020, 05:22:37 PM
To swing those bikesaws this equipment is very important.
I'm 62 and still using them everyday for over 40 years now :)
This is my gym in my laundry room. 

(https://forestryforum.com/gallery/albums/userpics/21589/20200417_135059.jpg?easyrotate_cache=1587158545)
Title: Re: HolmenTree bikesaw projects.
Post by: HolmenTree on April 17, 2020, 05:26:26 PM
Winter of 1988 running my YZ125.

Brother's Mac 101 kart saw beat me that day.
The experimental pipe's long stinger didn't work out.

(https://forestryforum.com/gallery/albums/userpics/21589/20200221_093507.jpg?easyrotate_cache=1587158774)
Title: Re: HolmenTree bikesaw projects.
Post by: HolmenTree on April 17, 2020, 05:32:28 PM
Brother Dennis with his 101 Mac with 34mm carb, inverted pipe stinger.

(https://forestryforum.com/gallery/albums/userpics/21589/Dennis1~0.jpg?easyrotate_cache=1587159139)
Title: Re: HolmenTree bikesaw projects.
Post by: HolmenTree on April 17, 2020, 05:41:43 PM
Also on that day Peter Holmquist Husqvarna distributor from Vancouver (originally farmed near our Saskatchewan farm) is running the first ever Husqvarna 3120XP in North America with a pipe. ;D

(https://forestryforum.com/gallery/albums/userpics/21589/20200221_092234.jpg?easyrotate_cache=1587159690)
 
Title: Re: HolmenTree bikesaw projects.
Post by: Walnut Beast on April 17, 2020, 10:35:20 PM
Yes sir!! That’s right! Getting after those weights makes a difference🏋️‍♀️🏋️‍♀️💪💪
Title: Re: HolmenTree bikesaw projects.
Post by: ehp on April 18, 2020, 03:16:58 PM
Jerry set a lot of records but if your talking about the 20 inch Boonville record I think was in 2017 , maybe a different year than that but I seem to know that chain very well he ran ;D, Dave won 2018 Boonville with a stock bore stock stroke  cr 250 from here . Just like everything else as time goes on things get faster
Title: Re: HolmenTree bikesaw projects.
Post by: HolmenTree on April 18, 2020, 04:26:22 PM
Jerry set a lot of records but if your talking about the 20 inch Boonville record I think was in 2017 , maybe a different year than that but I seem to know that chain very well he ran ;D, Dave won 2018 Boonville with a stock bore stock stroke  cr 250 from here . Just like everything else as time goes on things get faster
Yes it was the 20" Boonville record. There was discussion about it a few months ago on another forum talking about the high tooth chain.

Yeah those short stroke CR250 honda are pretty impressive. With my CR250 build I'm going into a whole new uncharted territory.
My '83 has the same basic bore/stroke and porting as the newer ones with non PV TRX design cylinder and CR500 style head.
A guy posted  his bikes dyno  sheet for his 1986 68mm x 72mm short rod  CR250 making 261cc.
Max power 57.05 at 7,460 rpm
Max torque  40.49 at 7,300
at the rear wheel!

It's going to be later this summer when I get the Honda in the wood, got to get the Yamaha done first so I know what to do with the Honda.
I definitely will find some .404 high tooth chain, I may have to pay a king's ransom for it though.
And definitely will run a 16T gear on it.
I thankyou for your usual good advice Ed. Hopefully I can get my tree service season started up this year to help pay for these extra custom parts.
Are you doing any logging?
They do need toilet paper and masks!!
Title: Re: HolmenTree bikesaw projects.
Post by: ehp on April 18, 2020, 07:54:09 PM
logging 7 days a week, just got home. What rpm are you spinning motor at . I know the cr 125 Honda I built the pipe for sure cut really well , Pipe was built for 11,250 rpms . Motor was stroked . It ran 3/8's chain but was never suppose to be in big wood . Big wood I would be running high tooth
Title: Re: HolmenTree bikesaw projects.
Post by: HolmenTree on April 18, 2020, 09:27:20 PM
logging 7 days a week, just got home. What rpm are you spinning motor at . I know the cr 125 Honda I built the pipe for sure cut really well , Pipe was built for 11,250 rpms . Motor was stroked . It ran 3/8's chain but was never suppose to be in big wood . Big wood I would be running high tooth
Good to hear you're busy putting timber in the landing!
The honda cr250r I haven't got it together to run yet. Got all new parts plus spares along with spare cylinder and crank. Enough to build 2 motors. One cylinder 66.75mm the other 68mm , both never ported, bores are mint and ready for a fresh hone.
It will run the 28" roller bar , 16T & 46RST, cone pipe, PVL analog ignition and SBN 38 carb.

The YZ125 I never had a tach on it, but with the factory 202°/129° port #'s it's peaky.
New cone pipe will be built and see how it runs with the SBN 38. Already setup and run in with the new PVL analog ignition.
It'll just run primarily the short roller bar and got it setup for .404 now .
Should have it in the wood in a few weeks.
Title: Re: HolmenTree bikesaw projects.
Post by: HolmenTree on April 19, 2020, 01:02:23 PM
So I'll try  both saws with the Mikuni SBN 38mm jetski gas carb. Then if it works out for both, the next new SBN 38 I'll buy will "probably" be a alky carb.
Not sure yet which motor will get the alky carb and the other running race gas.

(https://forestryforum.com/gallery/albums/userpics/21589/20191113_163831_resized.jpg?easyrotate_cache=1587315709)
 
(https://forestryforum.com/gallery/albums/userpics/21589/100_1110-2_28129.jpg?easyrotate_cache=1587315709)
 
(https://forestryforum.com/gallery/albums/userpics/21589/514ktSolAFL__AC_SY400_.jpg?easyrotate_cache=1587315708)
 
Title: Re: HolmenTree bikesaw projects.
Post by: HolmenTree on April 19, 2020, 01:17:37 PM
3.5 oz bar oil tank inside a 17 oz fuel tank. Got it all figured out now, just need to install 4 aluminum 1/4" fittings on the back, get it all tig welded together then cut the top to accept the gas/oil cap top plate and three bond 1194 gasket.


(https://forestryforum.com/gallery/albums/userpics/21589/20200419_120836.jpg?easyrotate_cache=1587316554)
 
Title: Re: HolmenTree bikesaw projects.
Post by: HolmenTree on April 19, 2020, 06:23:00 PM
Almost ready for tig welding.

(https://forestryforum.com/gallery/albums/userpics/21589/20200419_161029.jpg?easyrotate_cache=1587334933)
 
(https://forestryforum.com/gallery/albums/userpics/21589/20200419_160850.jpg?easyrotate_cache=1587334938)
 
(https://forestryforum.com/gallery/albums/userpics/21589/20200419_160838.jpg?easyrotate_cache=1587334941)
 
(https://forestryforum.com/gallery/albums/userpics/21589/20200419_160719.jpg?easyrotate_cache=1587334943)
 
Title: Re: HolmenTree bikesaw projects.
Post by: Evanguy on April 22, 2020, 06:31:28 AM
Holemen tree, wow i see this is not your first rodeo, its deffently mine so im excited to read this thread and learn. You have been doing this since before i was born ('85)

Also yeah the '83 top end wont fit on the 84 bottom end, if it did i would have used the 83 head to save weight and time. But ill just cut off the atac box on the 84 head to clean it up and make it lighter

I just ordered new rings and crank bearings for my build.

Im  a manual machinist who mainly runs a mill, but ive been layed off due to this covid 19 so my progress is slow right now.

What do you think about using the coolant jackets to hold the bar oil, and the drain hole as the output then pressurizing it with a small tube from near the stinger of the expansion chamber

Thats an awesome carb, now that i look around a bit more i notice lots of hot saws runs those carbs, they are off a jetski? What is the advantage over a flatside dirt bike carb? Say like a keihin pj 38 or a pwk 38 airstriker.

Once some more of my parts get here ill start a thread on my build. Also i hope to get into work for a day to get some work done on it. And back and forth if i should cut the cases. It will save a little weight but i have a hard time cutting stuff that is hard to come by ( i restore lee metfords and lee enfields as my main hobby)

Awesome thread, its been real helpfull.

There no chainsaw compaitions around here..so im building this just for fun so i can cut cookies in my yard. Can i use a 404  .080" harvester bar and chain with a 16 tooth rear? Or will the chain come off with out a fatbelly bar
Title: Re: HolmenTree bikesaw projects.
Post by: HolmenTree on April 22, 2020, 10:51:16 AM
Evanguy, first off my condolences to all you Nova Scotians in this time what you all are going through.
I was born and raised in Saskatchewan but I do have a first cousin in Bedford, Nova Scotia.
My family and I a few years ago toured on vacation all throughout Nova Scotia and we loved it along with all the great people we met.

There are many good competitions in the Maritimes many competitors into the Stihl Timbersport teams.
You gotta start somewhere in the smaller shows.

Your engine will be in a standup vertical profile so yeah bar oil in the cylinder water jacket works well. You really don't even need to pressurize it.
Just an inline valve to turn it on and off and let gravity and the suction of the drive links do its job.
My horizontal profile saw I need to keep all the extra weight I can at the front of the saw for good balance.

Yes that's a pumper jetski carb. I ran chainsaws most of my life with 2 adjustment screws and that's why I like this carbs setup.
I know nothing about dirt bike carbs.

Yes a .080 harvester bar is a good idea starting out, of course you'll need a .080 chain to match which unfortunately is semi chisel.
But with a motor pushing 50 hp semi chisel doesn't really matter for someone learning the ropes.
Just make sure no one is standing at any distance in front of your saw while your cutting . Think of shooting your Lee Enfield rifle.

If that chain breaks "chain shot" can pass through a solid steel guard.
Know your limitations!!

Matching the tail to a 16T .404 sprocket is so important that's where a harvester bar to match that diameter is so important.

One of my favorite rifles I owned is a Lee Enfield MK IV .303
I had a 4X scope on it and the rifling of the barrel was very good straight shooting. Tough rifle.
I heard  some of our WWll vets tell stories that they could smash a door open with the butt of that rifle.


Title: Re: HolmenTree bikesaw projects.
Post by: Evanguy on April 30, 2020, 10:05:47 AM
Thank you, and nova scotia is a nice place. i like it here, i from the halifax area but moved out of the HRM a few years ago now.
  
Ill have to check out some of the smaller shows and see whats up. I think there are some around but i cant really find any info online. Also im more so intrested in chainsaws then axes. Although that may change

Also this has been very helpfull to me. Loads of great info.

I got my top handle waterjetted out at work, still need to find time to weld it up between all my other projects lol.  I also sold all the inners of my 84 bottom end. So ill be cutting the cases to remove the transmission section.

Did you get any more work done on your motors?

Im going to start my build thread once this handle is finished. 
(https://forestryforum.com/gallery/albums/userpics/59944/Resized_20200429_094756.jpg?easyrotate_cache=1588255220)
 
Title: Re: HolmenTree bikesaw projects.
Post by: ehp on April 30, 2020, 10:10:32 PM
remember vibration is your real enemy so make sure you have as close to zero as you can get . the more the saw vibrates the harder it is to keep the chain on it . If your using .080 gauge chain you can buy bars from Oregon that fit up to 18 tooth , the one harvester  runs a 17 or 18 tooth gear
Title: Re: HolmenTree bikesaw projects.
Post by: snowstorm on May 01, 2020, 07:21:44 AM
i run a ctl harvester. i like sthil  chain doesn't break as often as others. sthil makes 2 one is heavier. oregon 18x cuts as good but weights less if that matters to you. the new 19x i was told takes a lot of hp. i have not tried it. a oregon speed max xl bar comes in lots of different widths and taper towards the sprocket. all 404  80 rakers at .050  
Title: Re: HolmenTree bikesaw projects.
Post by: HolmenTree on May 18, 2020, 08:30:03 PM
Little update here. My welder did a beautiful job welding up the YZ125 and cr250r fuel tanks with built in chain oil tank.
He used mig on the exterior and tig on the interior oil tank . These tanks are solid !
Now I can get the carbon fiber sideplates with bar pads all done up.
I'll have to do the project on the rainy off days as I'm  back into the start of my tree service season.

(https://forestryforum.com/gallery/albums/userpics/21589/20200515_153607.jpg?easyrotate_cache=1589848114)
 
(https://forestryforum.com/gallery/albums/userpics/21589/20200515_161238.jpg?easyrotate_cache=1589848106)
 
(https://forestryforum.com/gallery/albums/userpics/21589/20200515_155606.jpg?easyrotate_cache=1589848115)
 
(https://forestryforum.com/gallery/albums/userpics/21589/20200517_140001.jpg?easyrotate_cache=1589848108)
Title: Re: HolmenTree bikesaw projects.
Post by: realzed on May 18, 2020, 09:55:47 PM
See you are officially 'snowless' Willard - but maybe it is not a good thing to say that too loudly though just yet - eh?  
I made the mistake here and said that and we got 6" of the crap a week back a couple of days later..
Not bad weather now - but lots of stuff to get done with before our second season starts here (Bug Season) which I think will 'kick off' later this week!
Ever hear from your engineer friend from last years' accident?  Got wondering how he made out..
Randy
Title: Re: HolmenTree bikesaw projects.
Post by: HolmenTree on May 18, 2020, 10:51:32 PM
Randy, yes spring or maybe it's  summer now has finally sprung. It's calling for rain later in the week which will get the tree buds opening and get some much needed greenery.

No.I haven't heard from Chris since his train derailment accident, besides being one of his customers at his dealership we weren't all that close.
He sold his gas station and car wash and his wife and grandson are still running the Stihl dealership.
Yep really good people.
Title: Re: HolmenTree bikesaw projects.
Post by: HolmenTree on May 28, 2020, 04:22:31 AM
remember vibration is your real enemy so make sure you have as close to zero as you can get . the more the saw vibrates the harder it is to keep the chain on it . If your using .080 gauge chain you can buy bars from Oregon that fit up to 18 tooth , the one harvester  runs a 17 or 18 tooth gear
i run a ctl harvester. i like sthil  chain doesn't break as often as others. sthil makes 2 one is heavier. oregon 18x cuts as good but weights less if that matters to you. the new 19x i was told takes a lot of hp. i have not tried it. a oregon speed max xl bar comes in lots of different widths and taper towards the sprocket. all 404  80 rakers at .050  
I like the look of the 19X. Alot heavier then the 18X and cuts faster from reports.
Speed max XL bar and 16- 18 T sprocket looks like a good setup.

Oregon doesn't recommend the 19X on spur sprockets , they say rim sprocket only.
What do you guys think?



Title: Re: HolmenTree bikesaw projects.
Post by: olcowhand on May 28, 2020, 06:39:36 PM
Willard,
Until I started reading your posts, I didn't know the difference between a Spur Sprocket and a Rim Sprocket.... I personally think there's less "lash" in the Rim Sprocket over time. The Chain wears grooves in the Spur type.
For your application, I have no expertise or opinion, but I trust yours... I'm just following because you've got a cool build going.
Steve
Title: Re: HolmenTree bikesaw projects.
Post by: HolmenTree on May 28, 2020, 11:40:32 PM
Thanks Steve, I got plans for the 1992 066 too. :)
The spur sprocket is actually preferred turning the chain on these high powered hot saws.
I've always had one on my 37 year old Yamaha and I never threw a chain.

Now I'm thinking why Oregon recommends the rim sprocket on the new heavy fast cutting 19X harvester chain is dangers of chain shot.

This heavy 65 hp rated chain running with a 16-18 tooth sprocket would be putting out some major chain speed .
The result of breakage from a derail when the spurs teeth grap onto the chain can cause some serious damage. Especially when pieces of chain are flying everywhere.
We all know how little happens when we derail a chain on our chainsaws with a rim sprocket.
But the spurs if properly tensioned  are easier on the chain and derail less then a rim.
Title: Re: HolmenTree bikesaw projects.
Post by: HolmenTree on May 29, 2020, 09:44:13 AM
I can't find any information from the Stihl websites on harvester bars and chain.
Nothing pulls up on a google search.
Title: Re: HolmenTree bikesaw projects.
Post by: HolmenTree on June 10, 2020, 10:40:45 AM
Still pecking away at the projects. 
Limited time as my tree service season is full on.

(https://forestryforum.com/gallery/albums/userpics/21589/20200610_094046.jpg?easyrotate_cache=1591800032)
 
Title: Re: HolmenTree bikesaw projects.
Post by: snowstorm on June 10, 2020, 12:00:00 PM
I use sthil.404 harvester chain. As far as I know it’s still made. Only bought one of there harvester bars. That was enough. It was made in Brazil. No give to it and it broke. The best bar is painted blue. Lggesund forest. One tuff bar
Title: Re: HolmenTree bikesaw projects.
Post by: HolmenTree on June 10, 2020, 02:39:05 PM
I use sthil.404 harvester chain. As far as I know it’s still made. Only bought one of there harvester bars. That was enough. It was made in Brazil. No give to it and it broke. The best bar is painted blue. Lggesund forest. One tuff bar
snowstorm,  this must be for a processor you're running not a hand held hotsaw....or you'd have arms big enough to rip trees out of the ground breaking that bar :D
Title: Re: HolmenTree bikesaw projects.
Post by: Tacotodd on June 10, 2020, 03:45:43 PM
I know that I’m still looking forward to more of this thread. I’m looking forward to it every time I log on. I guess my wants are small, but I bet that you all would like to see how it comes out as well. Yes, I mean EVERYONE, including you, Willard.
Title: Re: HolmenTree bikesaw projects.
Post by: HolmenTree on June 10, 2020, 10:31:45 PM
Yes Tacotodd I'm pumped :D
Going from a 125cc bikesaw to a 250cc model is new uncharted territory for me. Will definitely keep the rakers higher on this one.
Title: Re: HolmenTree bikesaw projects.
Post by: Air Lad on June 11, 2020, 03:36:07 AM
So I'll try  both saws with the Mikuni SBN 38mm jetski gas carb. Then if it works out for both, the next new SBN 38 I'll buy will "probably" be a alky carb.
Not sure yet which motor will get the alky carb and the other running race gas.

(https://forestryforum.com/gallery/albums/userpics/21589/20191113_163831_resized.jpg?easyrotate_cache=1587315709)
 
(https://forestryforum.com/gallery/albums/userpics/21589/100_1110-2_28129.jpg?easyrotate_cache=1587315709)
 
(https://forestryforum.com/gallery/albums/userpics/21589/514ktSolAFL__AC_SY400_.jpg?easyrotate_cache=1587315708)

Crikey... My old RM250B had a 36mm Mikuni . Come to think of it my 900 Ducati had 2 x 40 mm Delorto's ,that's 40mm each 450cc cylinder( actually the 900 Duc was 864cc, but still?). Enjoying seeing your project/s unfold  smiley_thumbsup
Title: Re: HolmenTree bikesaw projects.
Post by: HolmenTree on June 11, 2020, 10:14:32 AM
So I'll try  both saws with the Mikuni SBN 38mm jetski gas carb. Then if it works out for both, the next new SBN 38 I'll buy will "probably" be a alky carb.
Not sure yet which motor will get the alky carb and the other running race gas.

(https://forestryforum.com/gallery/albums/userpics/21589/20191113_163831_resized.jpg?easyrotate_cache=1587315709)
 
(https://forestryforum.com/gallery/albums/userpics/21589/100_1110-2_28129.jpg?easyrotate_cache=1587315709)
 
(https://forestryforum.com/gallery/albums/userpics/21589/514ktSolAFL__AC_SY400_.jpg?easyrotate_cache=1587315708)

Crikey... My old RM250B had a 36mm Mikuni . Come to think of it my 900 Ducati had 2 x 40 mm Delorto's ,that's 40mm each 450cc cylinder( actually the 900 Duc was 864cc, but still?). Enjoying seeing your project/s unfold  smiley_thumbsup
Moto cross engines with reed valve intakes from about 1981 and newer have huge intake and port flow.
My YZ125 was handling no problem a 40mm + snowmobile carb.
These 125 mx motors have port flow with much higher rpm capabilities to match the larger 250cc engines.
I'm thinking running the same size 38 SBN on both 125 and 250 hotsaws.
But there is one other similar carb in 38 and 40mm that the Honda cr250r may get.
I've decided Alcohol fuel is no longer in my plans. Definitely will not run it now.
Title: Re: HolmenTree bikesaw projects.
Post by: HolmenTree on July 08, 2020, 10:01:59 AM
@Evanguy (https://forestryforum.com/board/index.php?action=profile;u=49944)
How is your 1984 CR250R hotsaw project progressing?
I have a photo here of a rough mock up of my 1983 CR250R project.
I found a CR250R 2003/04 FMF Fatty pipe from Royal Distributing (@ehp) hometown area. They blew them out on sale for $259 ($170USD). Can't go wrong with that!
Also bought 3 harvester .080" bars out of Alberta for $100 each. 22" 25" 28". The "22 was back ordered and coming to my door this week.
Harvester chain coming out of Quebec.

Now to get the fuel / oil tank moved 2" rearward and bolted in. Modify the pipe and get it mounted.

(https://forestryforum.com/gallery/albums/userpics/21589/20200630_121901.jpg?easyrotate_cache=1594216901)
 
(https://forestryforum.com/gallery/albums/userpics/21589/20200629_183525.jpg?easyrotate_cache=1594216903)
 
Title: Re: HolmenTree bikesaw projects.
Post by: joe_indi on July 09, 2020, 11:41:12 AM
Willard, I am on a couple of bike groups especially the 2 Strokes of the early 80s. It would really be something to see your Yamaha powered saw in action.
Would it be possible for you to upload a clip to YouTube and post a link.

Please! smiley_biggrin01
Title: Re: HolmenTree bikesaw projects.
Post by: HolmenTree on July 09, 2020, 02:40:44 PM
Joe,
I will have videos to post in a month or 2.
I have no videos of the YZ125 cutting when last filmed over 30 years ago. My brother has some on VCR tape that could be transferred to digital DVD. But he lives half way across the country.

The 1980's motorcycle 2 strokes were very strong and simple to work on.
My 1983 Honda CR250 design is the last year with a cast iron sleeve and no exhaust power valve.
1984 Honda introduced aluminum cylinder bores plated with Nikisel and the complicated power valve in the exhaust port.

In 1997 Mr Honda admitted the transition to Nikisel in 1984 was for cost savings and faster factory production runs. But cast iron lined aluminum cylinders were more superior in lubricancy,  better compression capabilities and more rigid durability for maximum power.
Title: Re: HolmenTree bikesaw projects.
Post by: ehp on July 09, 2020, 09:16:23 PM
you sure that pipe is going to work on the 250, totally different engine design , 2002 to 2007 cr engines are different than the test 
Title: Re: HolmenTree bikesaw projects.
Post by: ehp on July 09, 2020, 09:23:11 PM
your pipe is for a crankcase with reed block mounted in it, your motor has that on the cylinder , port timing is different as well
Title: Re: HolmenTree bikesaw projects.
Post by: HolmenTree on July 09, 2020, 10:03:49 PM
No problems Ed. This is a Fmf 2003-2004 CR250R pipe.
The 2003 CR250R has stock 188-189°exhaust with 129-130° transfer porting same as what my 1983 CR250R will be ported to.
Plus same bore stroke,. Same identical exhaust transfer cylinder port design and sizes. Case reed versus my cylinder reed makes little or no difference .

I'm cutting the header pipe to fit my horizontal engine. Plus it will be adjustable for length for tuning.Same with an adjustable stinger.
It will take some adjusting and testing but will all work out.
Title: Re: HolmenTree bikesaw projects.
Post by: HolmenTree on July 09, 2020, 11:41:27 PM
Just to add...

Ideally a handmade cone pipe  custom built to a custom built blue printed engine is the ultimate way to go...but if no dyno testing is done the custom pipe may mean nothing even if the computer program says it should work that way.

This  2003 CR250R pipe fits my 1983 exhaust flange. Same interior port match also.
1992 to 2001 CR250R pipe flanges were completely different flange hookups.

The 2002 to 2007 CR250R engines were built in the lines of a high rpm road racer powerband.  This FMF fatty pipes give a bit more to these engines low end and mid range plus the same on top.

In the end I still may go 195° on the exhaust with the transfers left at 130° getting 36° blow down because my engine won't be a big bore , only 261cc....then I may order a custom built cone pipe.
Lots of 261cc CR250R bikes  out there pushing dynoed 57plus h.p.at the rear wheel and that's with full air filter and pipe silencers.

My wife and I have August long weekend 2021 booked for Squamish,B.C. Logger Sports. If there is one next year??
But in the meantime I have lots of time getting these 2 saws on board for testing.
I got my practice harvester bars and 99DL of the new chamfer chisel 19HX chain.
Who knows in the end I may end up with a custom GEM bar and Stihl HT chain.

Pic is the new .080 19HX chain compared to the older .063 Stihl harvester.
Beautiful chamfer chisel on the 19HX with  high depth gauges and a chassis that is rated for 65 hp and won't stretch like a Stihl  HT .063.
Perfect for practicing and testing.

(https://forestryforum.com/gallery/albums/userpics/21589/20200708_230024.jpg?easyrotate_cache=1594352364)
 


Title: Re: HolmenTree bikesaw projects.
Post by: HolmenTree on July 14, 2020, 08:21:19 PM
I don't understand how these Oregon harvester bars and chain are cheaper then regular chainsaw b/c

I got these 22" 25" 28" .404 .080 bars out of Edmonton, Alberta each for $100 CDN ($73 US) plus shipping.  
The 99DL 19HX harvester chain came out Quebec for $38 CDN ($28US) plus shipping.
Go figure...
Great practice and testing b/c for the CR250R bikesaw!


(https://forestryforum.com/gallery/albums/userpics/21589/20200714_183249.jpg?easyrotate_cache=1594772468)
Title: Re: HolmenTree bikesaw projects.
Post by: HolmenTree on August 06, 2020, 01:14:03 PM
My tree service isn't allowing any free time in the workshop tinkering with the hotsaw projects. 
So found a hour last night to clamp a bar/chain onto the Honda for motivation.  :D

(https://forestryforum.com/gallery/albums/userpics/21589/20200805_212248.jpg?easyrotate_cache=1596734031)
 
Title: Re: HolmenTree bikesaw projects.
Post by: lxskllr on August 06, 2020, 01:31:05 PM
What's the difference between a "practice" bar and a "production" bar in a race scenario? What's the practice bar lacking?
Title: Re: HolmenTree bikesaw projects.
Post by: SpaceBus on August 06, 2020, 01:44:32 PM
Wow, lots of great reading to do! 
Title: Re: HolmenTree bikesaw projects.
Post by: HolmenTree on August 06, 2020, 10:40:00 PM
What's the difference between a "practice" bar and a "production" bar in a race scenario? What's the practice bar lacking?
lxskllr,
These harvester bar/chain are .404 .080 rated for 25hp min/65hp max.
When you're testing and constantly practicing this heavy duty setup is a must when you're saw is pushing over 50 hp.
The expensive. 063 46RST high tooth race chain would be stretched and ripped to shreds.
Title: Re: HolmenTree bikesaw projects.
Post by: teakwood on August 07, 2020, 08:22:21 AM
That is some serious sprocket!! will give chain speed,wow
Title: Re: HolmenTree bikesaw projects.
Post by: HolmenTree on August 07, 2020, 09:45:27 AM
That is some serious sprocket!! will give chain speed,wow
That's just a small 14T .404 teakwood.
I have a 16T coming in the mail next week.
I bought the 14T for the bigger 22 inch diameter Douglas fir out on the west coast of B.C.
Title: Re: HolmenTree bikesaw projects.
Post by: HolmenTree on August 07, 2020, 10:44:27 AM
Anyone out there having experience speed bucking the 22" Douglas fir at Squamish  B.C. and other areas. 
Please send me a PM if you have any info on sprocket size etc.
I've never cut competition wood that big before.
Thanks. 
Title: Re: HolmenTree bikesaw projects.
Post by: HolmenTree on August 13, 2020, 11:30:34 AM
My local machinist here in the photo is making bolt on  starter rope pulleys for the Honda and Yamaha.
He has a well equipped shop and been in it for over 40 years.
Last pic is my work bench.

(https://forestryforum.com/gallery/albums/userpics/21589/1076.jpeg?easyrotate_cache=1597332572)
 
(https://forestryforum.com/gallery/albums/userpics/21589/20200811_211845.jpg?easyrotate_cache=1597332575)
Title: Re: HolmenTree bikesaw projects.
Post by: HolmenTree on August 13, 2020, 09:13:59 PM
Pulleys are on my work bench. 

(https://forestryforum.com/gallery/albums/userpics/21589/20200813_203829~1.jpg?easyrotate_cache=1597369354)
 
(https://forestryforum.com/gallery/albums/userpics/21589/20200813_153549.jpg?easyrotate_cache=1597367625)
 
(https://forestryforum.com/gallery/albums/userpics/21589/20200813_153607.jpg?easyrotate_cache=1597367622)
 
Title: Re: HolmenTree bikesaw projects.
Post by: Magicman on August 14, 2020, 08:43:53 AM
 :o  That sprocket looks like it could go on a combine.  8)
Title: Re: HolmenTree bikesaw projects.
Post by: HolmenTree on August 14, 2020, 10:30:53 AM
:o  That sprocket looks like it could go on a combine.  8)
Indeed :D and it's just a medium sized one!
Speaking of farm equipment I remember wrapping a rope around the starter pulley on a Wisconsin powering my Dad's swather.
Not such a big deal like flywheel hand starting a John Deere D with the petcocks open but makes one appreciate electric starters.   ;D
Title: Re: HolmenTree bikesaw projects.
Post by: HolmenTree on August 21, 2020, 05:19:35 PM
I will have the little YZ125 in the wood soon, the Honda CR250 will be saved for last.

My machinist did a great job on the drive sprocket and rewind pulley. 
I got the PTO side dust seal perfectly centered to the crankshaft on my own.

(https://forestryforum.com/gallery/albums/userpics/21589/20200821_160602.jpg?easyrotate_cache=1598044740)
 
(https://forestryforum.com/gallery/albums/userpics/21589/20200821_161508.jpg?easyrotate_cache=1598044758)
 
Title: Re: HolmenTree bikesaw projects.
Post by: HolmenTree on August 31, 2020, 03:12:30 PM
My construction journey is slowly coming to an end. 
Saw's profile foundation is done. 
Now to cutting the top handle sideplates to balance and start bolting on pieces.

(https://forestryforum.com/gallery/albums/userpics/21589/20200830_213130.jpg?easyrotate_cache=1598901125)
 
(https://forestryforum.com/gallery/albums/userpics/21589/20200831_130445.jpg?easyrotate_cache=1598901120)
 
(https://forestryforum.com/gallery/albums/userpics/21589/20200830_214045.jpg?easyrotate_cache=1598901120)
 
Title: Re: HolmenTree bikesaw projects.
Post by: HolmenTree on September 06, 2020, 10:25:48 AM
Another mockup profile pic, this time the YZ125. 
My welder tig welded the pipe back together . I'm now making the mount brackets for him to weld on, plus he'll bend the stinger pipe away to the side  from the rear handle.

(https://forestryforum.com/gallery/albums/userpics/21589/20200904_205105.jpg?easyrotate_cache=1599402329)
 
(https://forestryforum.com/gallery/albums/userpics/21589/20200904_205233.jpg?easyrotate_cache=1599402325)
 
Title: Re: HolmenTree bikesaw projects.
Post by: HolmenTree on October 01, 2020, 11:00:18 AM
It's official guys, I now have a third hot saw project.
I just won an auction on Ebay for a 1984 Honda CR500 cylinder, piston and complete intake assembly.  A friend is shipping me a crankcase set from Oregon. Just need to find a head and crankshaft.
Research tells me this 1984 engine was the most powerful CR engine Honda ever built.
It's the last air cooled model (I'm removing 2/3 of the cooling fins)
What made it so powerful was its short 139mm connecting rod and was the only CR500 ever to have the large oval open exhaust port. All the other years the CR500 had the restricted bridged exhaust port.

Got it all covered now 125cc 261cc 500cc.
Title: Re: HolmenTree bikesaw projects.
Post by: Air Lad on October 02, 2020, 04:37:21 AM
Honda has become an icon for qualityt machinery worldwide
The "Red devil" motocross bikes were something special
smiley_wavy
Title: Re: HolmenTree bikesaw projects.
Post by: SpaceBus on October 03, 2020, 07:04:13 PM
500cc two stroke chainsaw sounds insane. That engine in the right hands could make close to triple digit horsepower. 
Title: Re: HolmenTree bikesaw projects.
Post by: HolmenTree on October 03, 2020, 09:45:35 PM
500cc two stroke chainsaw sounds insane. That engine in the right hands could make close to triple digit horsepower.
Naturally aspirated  with a big bore P/C and the right pipe  ignition,  squish and carburetion you may get 90hp maybe.
With nitrous yes 3 digits. But then you'd need 3/4" pitch harvester chain to keep up with that kind of power.
You won't find me on the operating end of that saw. Hahaha.
Stihl Timbersports event hotsaws are running in the neighborhood of 60 to 75  hp max at the crank.
The old high revving short stroke Rotaxs were getting more but not as nimble and now since Stihl Timbersports are running smaller diameter wood the lower powered and lighter saws are winning.

The new Wankels are putting out incredible horse power.
Title: Re: HolmenTree bikesaw projects.
Post by: realzed on October 04, 2020, 12:24:07 AM
Why "removal of 2/3 of the cooling fins" Willard?  
Do you really save very much weight for actually doing this and is that  the real reason - or is there other logic at play here, like clearance issues or ? to make it worth the effort?
I would imagine the more cooling effect the better as the horsepower gets pushed up..  
Title: Re: HolmenTree bikesaw projects.
Post by: SpaceBus on October 04, 2020, 06:49:19 AM
500cc two stroke chainsaw sounds insane. That engine in the right hands could make close to triple digit horsepower.
Naturally aspirated  with a big bore P/C and the right pipe  ignition,  squish and carburetion you may get 90hp maybe.
With nitrous yes 3 digits. But then you'd need 3/4" pitch harvester chain to keep up with that kind of power.
You won't find me on the operating end of that saw. Hahaha.
Stihl Timbersports event hotsaws are running in the neighborhood of 60 to 75  hp max at the crank.
The old high revving short stroke Rotaxs were getting more but not as nimble and now since Stihl Timbersports are running smaller diameter wood the lower powered and lighter saws are winning.

The new Wankels are putting out incredible horse power.
Even 75 Horse is out of control for a chainsaw! What's the fuel consumption per minute on something like that? 
Title: Re: HolmenTree bikesaw projects.
Post by: HolmenTree on October 04, 2020, 10:49:46 AM
realzed and SpaceBus,

Maybe I posted a little too much information. My projects are for race use only. They will only run wide open throttle for 5 to 10 seconds in a competition . No cooling is needed.

Rules are 1 minute warmup allowed up on the stage , that's warming it up then shutting it off , putting hands on log and waiting for the starting command.
These saws need to warm up fast hence the reduction in cooling fins.
They must be in the peak state of tune to start on the first pull of the rope and be at WOT into the 1st of 3 cuts.

Now you think that is hard, now look at the fact you must make 3 complete cuts with all that hp within 6 inches of wood. If you don't your disqualified  :D

Title: Re: HolmenTree bikesaw projects.
Post by: Mad Professor on October 04, 2020, 11:22:20 AM
Great thread!

Brings back memories of my dirt bike days of the 70s-80s.

I had a friend who put one of the air cooled CR500 motors in a Husqvarna WR frame, he called it a Hondavarna.
Title: Re: HolmenTree bikesaw projects.
Post by: thecfarm on October 05, 2020, 06:33:43 AM
Now you think that is hard, now look at the fact you must make 3 complete cuts with all that hp within 6 inches of wood. If you don't your disqualified  :D
And in how many seconds?  ;)
Title: Re: HolmenTree bikesaw projects.
Post by: HolmenTree on October 17, 2020, 01:03:08 PM
Guys, nothing to show besides a pile of parts of the two saws.
Presently glass bead blasting the cylinders, heads and crankcases.
Then rebuilding both engines with NOS OEM parts from bottom up.

As I said earlier seeing the Covid 19 may outlast my two hotsaw projects I'm starting to gather Honda CR500R engine parts for the third hotsaw project.
I got this freshly bored and honed 1984 CR500R cylinder and brand new piston from out of Newfoundland, Canada.  It's a 91mm bigbore displacing 514cc.

This first year CR500 with it's big oval exhaust port with very aggressive port numbers along with a short rod crank was the most powerful CR500 that ever came out of the factory.
Removing the majority of cooling fins will reduce a lot of weight for its 5 to 10 second runs at WOT.

I have a matched set of crankcases coming out of Oregon as I speak.

(https://forestryforum.com/gallery/albums/userpics/21589/20201016_150025.jpg?easyrotate_cache=1602954174)
 
(https://forestryforum.com/gallery/albums/userpics/21589/20201016_152555.jpg?easyrotate_cache=1602954174)
Title: Re: HolmenTree bikesaw projects.
Post by: Tacotodd on October 18, 2020, 12:00:50 AM
Willard, that’s a big piston for a lot of automobiles!
Title: Re: HolmenTree bikesaw projects.
Post by: HolmenTree on October 18, 2020, 04:48:31 AM
Willard, that’s a big piston for a lot of automobiles!
Tacotodd, it sure is big alright.  I can put my hand inside the cylinder with no problems.  Easy to work on .
Title: Re: HolmenTree bikesaw projects.
Post by: mike_belben on October 18, 2020, 08:02:14 AM
In my teens i rode a CR500 once, and a quadzilla 500 once.  Both bikes that you didnt beat on... They beat on you.  You had to look for spots to crack the throttle just to hear what the top end was like because in the northeast woods there was nowhere with room enough to open them up for more than a few seconds.  So it was a blip here and blip there to stay on a 125 or 250. If you were out front and doing more than blips, you were going too fast for the trail pretty much instantly.  


Where i could keep my 250 to maybe 70% output, a 125 to 80% and a 80cc to 95 or 100% output most of the time,  the 500cc stuff was the bike putting out 40% and me at 105.  Injury speed in an instant, just twist and the front comes up.  
Title: Re: HolmenTree bikesaw projects.
Post by: HolmenTree on October 18, 2020, 11:55:36 AM
Mike, I've never ridden a 500 or 250 but from YouTube videos of the guys on a CR500 some didn't even use 1st or 2nd gear. ;D
Bikes are tractors from how they pull the front wheel up with a rooster tail of dirt off the back wheel.
One video of a CR500 hotsaw the operator didn't rev it to WOT before hitting the log, it just opened up in the wood.
Title: Re: HolmenTree bikesaw projects.
Post by: HolmenTree on October 18, 2020, 01:03:02 PM
CR 500 chainsaw - YouTube (https://youtu.be/j9dIvorjx1w)
Title: Re: HolmenTree bikesaw projects.
Post by: mike_belben on October 18, 2020, 02:56:44 PM
Yeah exactly.. They have so much piston pushing on so much crank that they dont need rpm. Probably dont have the carb and ports for putting it all up top id bet.  But they can torque out of any hole in any gear. 

I had a husky 250 when i was about 13 .. I think it was a WR.. Similar power but you could use it a lot more often than a 500 in the woods.  It was flat power from bottom to mid.. Once you used up the mid it would rev higher but not pull harder.  If you upshifted it dropped rpm back into the curve and pulled again.  Whenever the rpm got low it had almost excess power, [for a kid anyway] almost didnt matter what gear. 


When i got a 450R fourstroke quad.. That was similar.  They feel like big blocks.  Like a truck engine in a minibike.  A cat 550 isnt that much different.  Keep piling on weight and they just keep pulling it up the hill without revving any higher.  Torque is nice for lazy riding. Its tolerant or your errors and doesnt take 3 shifts to fix a bog at the bottom of a hill. It just ripsaws its way up. Braaahpp.  

I probably cant even start a dirtbike anymore.  Now im feelin old!
Title: Re: HolmenTree bikesaw projects.
Post by: HolmenTree on October 18, 2020, 06:00:47 PM
The CR500 will sing at top end at about 7500 rpm by raising the exhaust port enough and milling .080" off the head.
Lots of potential. 
Title: Re: HolmenTree bikesaw projects.
Post by: HolmenTree on October 28, 2020, 11:00:43 PM
I'm slowly piecing the 1984 Honda CR500R 514cc hotsaw project.
The new OEM short rod crank with billet Crankworks Pro Rods kit came tonight. Now I can do a mock up profile picture.
It will look much different when near finish,  2/3rds of the cooling fins gone, no transmission housing.
Major porting will be done with other bolt on performance parts greatly exceeding its stock 60 hp and 50 ft lbs of torque.

(https://forestryforum.com/gallery/albums/userpics/21589/20201028_195145.jpg?easyrotate_cache=1603940356)
Title: Re: HolmenTree bikesaw projects.
Post by: HolmenTree on November 04, 2020, 12:26:14 PM
well then you should know , the bigger the diameter of log the higher number of tooth the gear needs to be so the cutter cuts the full way across the block . If your cutter gets full it stakes the rest of the way across the block and starts bouncing in the cut . The chain your using we played lots with and went as high as 24 tooth gear on a rotax and after 20 tooth it made zero difference as was still a lot slower than high tooth setup running a 16 or 17 tooth setup
ehp,
I'm trying to decide what size .404 sprocket to put on the CR500
The 500 has the same size pto crank spline as the 250.
The 500 will peak at around 7000rpm with about 50 foot lbs of torque so I'm thinking no less then a 20 tooth .404.
I don't know anyone who has a CR500 bikesaw, might go 22T.
Title: Re: HolmenTree bikesaw projects.
Post by: HolmenTree on November 04, 2020, 11:08:02 PM
So here I'm doing a comparison of my NOS 1983 Honda CR250R crankshaft on the left in the first pic alongside the Honda CR500R crankshaft.
The 500 crank has NOS OEM webs with a custom CrankWorks Pro Rods billet short rod kit.

They each share the same main bearings and same size 21 spline journal stub to except the same custom sawchain sprocket.

The main difference between the two is the 16T sprocket sized for the CR250R won't offer enough competitive chain speed for the double the size slower rpm CR500R.
I'm thinking 22T .404 to run the 19HX harvester B/C on the 500 for testing and practicing.
For competition,  then I better look high and low for  .500" pitch Oregon 10AL sawchain and get a 18T paddle sprocket made.

(https://forestryforum.com/gallery/albums/userpics/21589/20201029_201709.jpg?easyrotate_cache=1604657964)
 
(https://forestryforum.com/gallery/albums/userpics/21589/20201028_185154.jpg?easyrotate_cache=1604657964)
 

Title: Re: HolmenTree bikesaw projects.
Post by: Tacotodd on November 05, 2020, 06:10:28 AM
Whhaaaat?????? I thought that you always went OE on pieces on “most” saws. I guess that this doesn’t qualify though ;D
Title: Re: HolmenTree bikesaw projects.
Post by: HolmenTree on November 06, 2020, 05:47:44 AM
In my last post I forgot to mention the evolution design of the Honda CR series crankshaft.

In the first pic below here's some more pics of my NOS 1983 CR250R crank for again comparison to the crankshaft for my 1984 CR500R engine.

1984 was the first year Honda went to the "tin can" web covers, the 1983 was the last year for solid webs and internal stuffer plates this design went on into the 1990's formula 1 road racing bikes.
1984 was also the first year for Honda's Pro lite design piston in the CR250 and CR500.

So my 1983 250 has a good foundation for a highly modified top end cylinder.

Last 2 pics are the mighty  91mm CR500R piston.  
To show the versatility thinking of Honda this piston will fit a 1982 CR480R all the way to 2001 CR500R.


(https://forestryforum.com/gallery/albums/userpics/21589/20201029_205127.jpg?easyrotate_cache=1604659360)
 

(https://forestryforum.com/gallery/albums/userpics/21589/20201028_131651.jpg?easyrotate_cache=1604659506)
 
(https://forestryforum.com/gallery/albums/userpics/21589/received_374377083590144.jpeg?easyrotate_cache=1604659504)
 
Title: Re: HolmenTree bikesaw projects.
Post by: HolmenTree on November 06, 2020, 05:58:03 AM
Whhaaaat?????? I thought that you always went OE on pieces on “most” saws. I guess that this doesn’t qualify though ;D
Hehe, yeah I had to do a little editing to keep in good standing ;D

:D
Title: Re: HolmenTree bikesaw projects.
Post by: Tacotodd on November 06, 2020, 07:00:23 AM
10-4! I was wondering.
Title: Re: HolmenTree bikesaw projects.
Post by: HolmenTree on November 20, 2020, 10:28:50 PM
Well tonight my YZ125 and CR250R bikesaw carbs came in all the way from sunny Santa Ana, California to up here in freezing northern Manitoba Canada.  Last of the major parts for my projects. 

Art Gomez did an excellent job modifying and blueprinting these carbs to my engines specs. 
While modifying my brand new 38mm carb he found some porosity so he welded it out and finished the job repainting the whole carb. 
Excellent work. Thanks Art

Next will be a 44mm BJ carb for the CR500R. 

(https://forestryforum.com/gallery/albums/userpics/21589/20201120_201855.jpg?easyrotate_cache=1605929313)
 
(https://forestryforum.com/gallery/albums/userpics/21589/20201120_205504.jpg?easyrotate_cache=1605929310)
 
Title: Re: HolmenTree bikesaw projects.
Post by: Tacotodd on November 21, 2020, 07:39:19 AM
Beautiful!!!  I was also wondering about your cataracts. Any update? Or am I mistaken? After all, any thing is possible, and some things are are highly probable. 

BTW, good to see you out there still plugging away!
Title: Re: HolmenTree bikesaw projects.
Post by: HolmenTree on November 21, 2020, 10:36:57 AM
Beautiful!!!  I was also wondering about your cataracts. Any update? Or am I mistaken? After all, any thing is possible, and some things are are highly probable.

BTW, good to see you out there still plugging away!
Hey thanks. 
Yep just finished my last eye last week. Got 2 new "made in Texas" lens installed, and all I can say is WOW with the bright colors I look at and no more cloudy white glare . Like cleaning a very dirty window.  :D
Due to the time frame of my double eye surgeries I have to avoid dust and heavy lifting, I've been taking it easy doing R&D.
Title: Re: HolmenTree bikesaw projects.
Post by: Tacotodd on November 21, 2020, 01:31:45 PM
Isn’t it hard to do much R&D? I mean, no heavy lifting and all. 

Don’t get me wrong, I know that quite a bit of R&D can be done just doing the “paperwork” research, but real world development comes from your doing it. And YOU are a hands-on type of man! I know that you are just ITCHING for that time (however long it is) to have passed. But even then, take it easy and follow the Docs orders. 

Just don’t be TO sedentary, blood clots might develop. Best thing that I’ve seen, hand wash some dishes. 2 things happen from that. It gives great appreciation for dishwashers, and makes you understand some of the lifestyle of a much older generation (back in the day)!
Title: Re: HolmenTree bikesaw projects.
Post by: HolmenTree on November 21, 2020, 09:24:25 PM
Tacotodd, well said. I can relate to alot of what you said.
When I was a kid on the farm running water was me running to the well with a bucket. Winter time was melting snow in a tub on the wood burning cook stove.

Every morning and late afternoon after school was chopping ice holes in the dugout to water 30 head of cattle and a few horses.
Dad and I put up hay for the livestock winter feed with a pull behind mower, hay rake, pitch forks and a hay rack wagon.

Lots of machinery fixing and putting in a crop on 2 quarters of land with a open cockpit gas tractor.
When I turned 16 I learned to cut and skid tree length softwood 8 hrs a day 5 days a week for many years.
Today turning 63 in a few months I'm settled in nicely running my own seasonal tree service operation with no employees. Life is good, but like my wife said I need to do some maintenance on myself  :D Clear vision is nice!

Still admiring my carbs I just got back from the builder.
How's this for flow blending?
Beautiful work on this 40mm.

(https://forestryforum.com/gallery/albums/userpics/21589/20201120_213750.jpg?easyrotate_cache=1606011739)