Hi Guys. Im new to the forum and am from Perth, Western Australia.
I bought the saw (oleo mac 952) about a year ago and used it for a season. I started it this year and it kept stalling. Even when warm. It would cut fine and as long as i revved it a little in-between cuts but as soon as i stopped revving it would stall. I took it to the chainsaw place where i bought it for a service and got a phone call 2 days later saying the piston was scored badly. they charged me 50 bucks and all they did was take the exhaust off and looked the the piston!! I told the bloke that i just wanted a service/carb adjustment as it was working and he said its stuffed. I got it home and screwed the high, low and idle all the way in and backed out the high and low one turn each. It worked and it also idled, I adjusted the idle so it sounded right (i don't know how to adjust it perfectly) and used it for about half an hour with no problems. it finally stalled on me again and then i adjusted the idle again and it worked fine. it then got a bit hot and stalled so i stopped using it. It still starts and idles now but i need to adjust it properly.
2 questions.
what are everyones opinions on weather or not the saw is stuffed and needs a new piston?
Does it sound like the saw just needs an adjustment?
It is defiantly scored (i can upload a photo) however the saw does run and also has compression when i pull to start it.
Help would be greatly appreciated :)
I also have a dolmar ps410 that i am working on, i am waiting on a fuel line for it, nice little saw. My 3rd saw is a 82cc Chinese one that i bought for a laugh. its not to bad considering i paid for 250 bucks.
Note the saws here in Australia cost a lot more then America. for example a MS 391 costs $1279.00 in Aus.
Hello shiggins,
All I will tell you is that with each run you are making the situation much worse! You obviously have no idea what you are doing and are doing everything possible to kill an actually very nice saw.
To be honest I am at the moment to tired to even try to explain anything, so all I will do is wish you good luck! Others will arrive shortly and I am sure help you out.
7
jeeze your a nice fella.
Thats why i am here mate. To learn.
I haven't been using it since last time because of the overheating. I thought that might have something to do with the carb adjustment. I am guessing you mean if i stop now i might be able to save the cylinder and only have to get a piston and rings? I also need to know why the piston got damaged as the fuel i was using was tested by the bloke at the store and it was fine. He asumed i had used the wrong mix before hand. I'm actually looking forward to learning how to swap out the piston/ cylinder if thats what is needed. I was told by the chainsaw store that it would cost 300 plus just in parts though
shiggins,welcome to the forum.
Thanks mate. :)
Shiggins, welcome to the forum.
When you kept adjusting the carb to keep it running, that was like putting a band-aid on a cut that really needs stitches. It didn't help much and could have made things worse. I think that's the point 7sleeper was trying to make...
If the piston is scored, it will need a new piston and ring\s. If you can upload a picture of the piston through the exhaust port, that would be very helpful.
Often times you can salvage the cylinder, if the plating isn't scored through. Aluminum transfer from the piston can be confused with a scored cylinder. There are multiple methods to remove the transferred aluminum.
And you're right, you need to figure out why the piston scored in the first place, or when you repair the saw, it will just do it again. Suspects here could be an air leak somewhere, causing a lean mixture, bad fuel (you said it was tested but don't rule it out, especially if there was old fuel when you first ran it this year) or the high speed jet was tuned too lean, overheated, etc.
Not sure how much luck you'll have finding parts for it.
Now, I've never worked on an oleo mac, I'm not familiar with that saw, but they all work the same way. You will get help here if you ask for it ;)
Thanks for the advise mate. So first step is to take it apart and see what the cylinder is like. Then i know what parts I need. Once repared I would need some Advice on adjusting the carby so it's running correctly and check for
A potential air leak.
Photos 2 come. I have them but it won't let me upload from my phone.
pics show all stages of piston moving. looks very badly scored
(https://forestryforum.com/gallery/albums/userpics/36650/photo_1%7E0.jpg)
(https://forestryforum.com/gallery/albums/userpics/36650/photo_2%7E0.jpg)
(https://forestryforum.com/gallery/albums/userpics/36650/photo_3%7E0.jpg)
Oh yeah that's toast (or is it stuffed?) ;D
@shiggins,
The nice fellow is back...
As feared you have done everything possible to ruin a good engine. It was obviously not a very smart thing to do and distrust the repair crew's opion...
The reason why your saw died is highly speculativ and will never be known and at this moment are totally irrelavent.
So what do we do now? The options are quite slim. First off you will have to completely dismantle your saw. Nothing further can be done from the outside. To be honest I hope you didn't ruin anything further in the inside.
So please completely dismantle your saw and make some pictures of the inside pieces of your engine, then it will be easier to recomend further procedures. There are many detailed threads on the internet on how to dismantle a chainsaw, please follow those procedures to prohibit further damage. If you have someone with experience in engine rebuilding that would be helpful.
I would suspect that you will require at least a new piston, rings and gaskets. Maybe as mentioned above the cylinder is salvagable, so that it is not a complete catastrophe. But to be honest I fear not. Parts will have to be original Oleo Mac = Efco because there are no aftermarket that I am aware of.
Good luck!
7
Thanks 7
Since it still runs in hoping it's just the piston and rings. The reason I didn't take the repair option was because it was almost the same price as the saw. But now when I look online I should be able to get the parts from America for 100 bucks. I'll report back soon
(https://forestryforum.com/gallery/albums/userpics/36650/piston1.jpg)
(https://forestryforum.com/gallery/albums/userpics/36650/cylinder_out.jpg)
the intake side of both the piston and cylinder are scored. the cylinder doesn't feel terrible with my finger but doesn't look good.
one ring was ceased.
Looks like I'm up for a new cylinder and piston kit. There is a tiny bit of play from side to side in the crank shaft as well.
where to go from here?
Read the online threads about salvaging a cylinder through acid. You might be lucky! Don't grind anything out only use acid.
CAVE: EYE protection and good ventilation is mandatory!!!
7
how much is a cylinder? Ill check it out. I either need to find a supplier here in perth or order the new gear over ebay
(Links to specific ebay ads deleted by Admins)
are these ok quality?
also is there anything else i should change out now while I'm doing this?
i found a video about sanding the cylinder. I would probably prefer to spend the money to make sure i get full compression
You can use muriatic acid, or even toilet bowl cleaner, and a 3M pad and alot of elbow grease. The plating on the cylinder is very tough. I would try and save it before buying a new one!
I understand i can get the cylinder in ok shape but won't the saw have less compression then a new cylinder. I am keen to learn how to get the cylinder back in shape so i still may as well give it a shot
shiggins, those photos might look frightening, but appearances could be exaggerated by the loose carbon and aluminum.
That cylinder is salvageable, no doubt about that.
And, if your luck holds good, ditto the piston.
You need to get all traces of aluminum deposits from the cylinder walls.(Muratic acid, cistern cleaner, emery, whatever)
Mark the upper and lower rings and take then off the piston carefully.
Use some emery to polish that piston (Horizontally)
Clean up the piston, dip it in fuel (with 2 stroke oil mixed ). Close the plug hole in the cylinder and drop the piston into the cylinder. If the piston goes down with some air resistance, that piston should be good for the present.
Use a flat file to level off the grooves on the rings. When you refit the rings, exchange their positions(upper ring in lower groove and vice versa)
Make sure the rings move freely in their grooves.
Oil the rings and re-assemble the engine.
Check for the reason for the seizure. It could be any one or more of these reasons :
Partially blocked pick up body (filter in the fuel tank) Replace
Partially blocked strainer in the carburetor . Clean
Lean setting of H and L screws. Turn them out 2 turns from the stop (that should raise some eyebrows)
Fill the fuel tank with fuel mixed with 4% oil
Before fitting the spark plug, with switch in Off position, prime the engine by dropping a capful of fuel into the air intake. With throttle wide open pull the starter a couple of times. Fit the plug, switch should be on, no choke, but partial throttle position, start her up.
If it starts up blip the throttle without holding high revs for too long. One the engine is warmed up, tighten the idle screw so that the engine idles without your hand on the throttle.
With screwdriver in place on H screw, take it to full revs and turn in the screw till the four stroking just stops, leave the throttle and back out the H screw by a little less than a quarter turn.
Turn in the idle screw to its stop to get a fast idle. Screw in L screw till idle increases. Back off the screw a bit. Set idle screw to a bit faster idle. You can readjust the carb once the piston has seated a bit. After a couple of tankfuls you can switch back to the normal mix of two stroke oil.
Good luck
Joe
@shiggins,
You see what I meant!? Other real smart guys have arrived to help you out! I'm just a little dwarf on the side line when these boys come by and tell you what to do! Now do yourself a favor and listen carefully. Then you might have a nice working saw in the end!
7
Thanks guys. One of the rings is ceases on the piston and won't come off. I will try to clean up the cylinder. There is still compression now. As I said it was still running. Unfortunately the ring is ceased so I might need to get a new piston. If I can do this it's only going to cost me under 50 bucks. Ill try and clean it up and get a photo uploaded
(https://forestryforum.com/gallery/albums/userpics/36650/1.jpg)
(https://forestryforum.com/gallery/albums/userpics/36650/2.jpg)
(https://forestryforum.com/gallery/albums/userpics/36650/3.jpg)
(https://forestryforum.com/gallery/albums/userpics/36650/4.jpg)
its looking better. when i drop the damaged piston in with no rings it defiantly slows as it pushes air through. The scores u can see i can badly feel now. feels smooth
This damage came from a lack of oil not a lean setting or air leak. Steve
Well the cylinder is looking good shiggins!
Anywhere there is a mark, use your fingernail and run it across the marks. If your nail catches, it's not smooth enough yet.
Have you located a piston\rings set yet?
Thanks mate. I'm going to ring around tomorrow as we had a public holiday today. I've found them online but will look local first. I might need a new gasket and bearing as well?
How do u know it was fuel mix ladylake ? I would love to know
Saws run lean will score on the exhaust side, most time just if front of the exhaust port. Without oil they score all the way around or most of the way around. Did you use fresh gas mixed right preferably with out ethanol and shake it up. Steve
The piston isn't scored on the intake side. I am very carful with my mixes. It was still working so the damasge could of happened a while ago. Maybe I did make a mistake a while ago. Could of been old fuel that settled down. Is hard to pinpoint now.
Just getting local prices on the piston and also checking cylinder price.
Online I have found them for $90 in the states as that's for the whole cylinder kit.
The price I got here is 150 just for the piston and rings or 536 for the whole cylinder kit. What's the go here? Chinese vs genuine? Thoughts?
I am still getting more quotes.
Edit
Best local quote ATM is 100 for piston and rings and 320 for cylinder kit. I'll need to get a new gasket as well. It's stuck to the cylinder and is ripped.
To be honest I would get the set from the US if it was genuine. I would save the old cylinder and just put in the new set. Further I would renew all the seals, carb boot, impuls line, etc. just for safety reasons. You will have a practically new saw then, but with proper care this time it should last a life time!
7
Quote from: 7sleeper on June 03, 2014, 01:57:36 AM
To be honest I would get the set from the US if it was genuine. I would save the old cylinder and just put in the new set. Further I would renew all the seals, carb boot, impuls line, etc. just for safety reasons. You will have a practically new saw then, but with proper care this time it should last a life time!
7
7 can you do me a favour and explain to me how many and what seals the saw has, the carb boot is the rubber part that attaches to the cylinder (I've got that), what is the impulse line ( is it the line from the carby to the cylinder?) I will try to find a new cylinder gasket. Anything else I need?
Sorry mate but I'm new to all of this. I also don't know how to tell if they are genuin pistons. It does say aftermarket and are from Canada. It would be 50 bucks cheaper from eBay compared to my local.
Quote from: shiggins on June 02, 2014, 09:03:38 PM
The piston isn't scored on the intake side. I am very carful with my mixes. It was still working so the damasge could of happened a while ago. Maybe I did make a mistake a while ago. Could of been old fuel that settled down. Is hard to pinpoint now.
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In post number 11 you said it was scored on the intake side, either way when run lean the scoring will be on the exhaust side, no oil or separated junk ethanol it will be all the way around like your piston looks. Steve
Thanks Steve
I've gone local with the parts. Ordered a piston kit and gasket. The piston kit is $100. That's $50 more then eBay but I would have to wait a while from eBay and im not ute about the quality of the eBay kit and import taxes ect. I'm also getting the manifold gasket.
I'll upload some pics of the cylinder tonight. It's looking good
(https://forestryforum.com/gallery/albums/userpics/36650/new1.jpg)
(https://forestryforum.com/gallery/albums/userpics/36650/new2.jpg)
(https://forestryforum.com/gallery/albums/userpics/36650/new3.jpg)
(https://forestryforum.com/gallery/albums/userpics/36650/new4.jpg)
thats about it i think. what do you fellas reckon?
What we were expecting!
7
Looks like it cleaned up real good.
Wasn't too hard, just took alot of elbow grease, huh?
Yeh just some elbow grease! lol. now I just wait on the piston and gasket and install. Thanks for the help so far guys.
Well the new
Piston is in and I followed Joe_indi instructions. Only problem I have is tuning. This saw has a pre set high and low so I can only back it out one turn on each high and low.so u can only adjust the high and low by half a turn. The idle can be adjusted as much as I want though.
Quote from: shiggins on June 13, 2014, 06:21:36 AM
..........Only problem I have is tuning. This saw has a pre set high and low so I can only back it out one turn on each high and low.so u can only adjust the high and low by half a turn. The idle can be adjusted as much as I want though.
Ahem, nothing prevents you from creating a suitable tool to extract the limiter caps on those screws so that you could do some decent tuning.
Quote from: joe_indi on June 13, 2014, 01:00:36 PM
Quote from: shiggins on June 13, 2014, 06:21:36 AM
..........Only problem I have is tuning. This saw has a pre set high and low so I can only back it out one turn on each high and low.so u can only adjust the high and low by half a turn. The idle can be adjusted as much as I want though.
Ahem, nothing prevents you from creating a suitable tool to extract the limiter caps on those screws so that you could do some decent tuning.
This is true Joe,
The high sounds about right though after adjusting it only in the range the saw gives me. obviously i get the saw to a good idle as well. will this be sufficient? i would of thought these are set from the factory and should allow the user to only adjust only enough for change of climate. I am only a novice though. would you still take the restrictor parts off and adjust it your way? Thanks Joe
Quote from: shiggins on June 14, 2014, 01:11:50 AM
Quote from: joe_indi on June 13, 2014, 01:00:36 PM
Quote from: shiggins on June 13, 2014, 06:21:36 AM
..........Only problem I have is tuning. This saw has a pre set high and low so I can only back it out one turn on each high and low.so u can only adjust the high and low by half a turn. The idle can be adjusted as much as I want though.
Ahem, nothing prevents you from creating a suitable tool to extract the limiter caps on those screws so that you could do some decent tuning.
This is true Joe,
The high sounds about right though after adjusting it only in the range the saw gives me. obviously i get the saw to a good idle as well. will this be sufficient? i would of thought these are set from the factory and should allow the user to only adjust only enough for change of climate. I am only a novice though. would you still take the restrictor parts off and adjust it your way? Thanks Joe
The fact that the crown of your original piston melted so it could seize the upper ring tells me that the engine was running too lean, no matter the shortage of mix oil.
Thus I'd be sure to be able to adjust the H mixture as required to be certain not to melt things again.
When it's adjusted right, after being warmed up, the engine will 2-stroke @WOT under full load, then transition to 4-stroking when you lift. Lots of info you can "google" on those and how to get there.
Going forward, dump tank when storing saw for more than a few weeks, use FRESH mix and pure-syn oil meeting both these specs: JASO FC or FD, ISO-L-EGD at 40:1. Lots cheaper than engines. Store all the fuel in a cool/dry place- helps avoid moisture probs.