The Forestry Forum is sponsored in part by:

iDRY Vacuum Kilns


Forestry Forum
Sponsored by:


TimberKing Sawmills



Toll Free 1-800-582-0470

LogRite Tools



Norwood Industries Inc.




Your source for Portable Sawmills, Edgers, Resaws, Sharpeners, Setters, Bandsaw Blades and Sawmill Parts

EZ Boardwalk Sawmills. More Saw For Less Money!

STIHLDealers.com sponsored by Northeast STIHL


Woodland Sawmills

Peterson Swingmills

 KASCO SharpTech WoodMaxx Blades

Turbosawmill

Sawmill Exchange

Michigan Firewood, your BRUTE FORCE Authorized Dealer

FARMA


Baker Products

ECHO-Bearcat

iDRY Wood Lumber Vacuum Drying for everyon

Nyle Kiln Dry Systems






Author Topic: fuel mixture  (Read 10096 times)

0 Members and 1 Guest are viewing this topic.

Offline woodsdog2015

  • Full Member x2
  • ***
  • Posts: 172
  • Location: Western New York
  • Gender: Male
  • Newbie Woodcutter
    • Share Post
fuel mixture
« on: December 14, 2015, 09:46:37 PM »
Ok I recently watched a video on youtube from a trusted source and this person explained that they run a 32:1 mixture in all of their saws.  Three of the four saws I own require 50:1 the big Homelite 8800 I have requires 32:1..... I'm asking the pros or the sawshop owners or both on their opinions about this.  I have two stihls and an echo too and the owners manuals all recommend 50:1.  Does it void the Stihl warranty to run a mixture with a little more oil? Does it protect the components better?  What are your recommendations???? 
I'd rather be in the woods.
MS362CM
MS251
CS-300
Homelite 8800
FiskarsX27

Offline Jiles

  • Full Member x2
  • ***
  • Posts: 135
  • Age: 74
  • Location: Florence Alabama
  • Gender: Male
  • Here to Learn and maybe Teach
    • Share Post
Re: fuel mixture
« Reply #1 on: December 14, 2015, 10:26:07 PM »
That same person that advised to use 32:1 ratio, probably changes his auto oil every 3K miles.
Modern two stroke oil is vastly superior to what we had years ago.
With that being said, I have worked on small engines for over fifty years and it is my opinion that  50-1 is an EPA forced requirement. I personally like to run app 40:1 and tune the saw for that mix.
Instead of 2.6 oz. to one gallon, I just add 3 oz.
Be advised that the modern two stroke is an extremely high output engine, for its size, and is greatly effected by carburetor mixture.
When I sell a chainsaw, I advise them to use non ethanol premium gasoline and a high quality oil and if they use lower octane gas, or use 2.6 oz., it needs to be tuned for it.
It's just that critical.
Also, I would not think 32-1 mix would damage anything other then maybe fouling sparkplug if lugged or allowed to idle for long periods.
As far dealer approval, I would not know, but I think most would advise against it.
Satisfy needs before desires

Offline Ianab

  • Administrator
  • *****
  • Posts: 13521
  • Age: 57
  • Location: Stratford , New Zealand
  • Gender: Male
  • Marmite on toast is a real breakfast
    • Share Post
Re: fuel mixture
« Reply #2 on: December 14, 2015, 10:28:47 PM »
When I bought my Stihl and Dolmar saws the dealers specifically told me to ignore the oil mix in the manual, and mix at 25:1. Explanation was that NZ gas is formulated differently and needed more oil. This wasn't just a couple of hick dealers either, the NZ bottled Dolmar oil that came with the saw had the 25:1 ratio on it, so it was the official distributor policy, and as far as I know it still is.




This leads me to believe that running more oil is not going to cause any issues. Now you are probably fine running 50:1 with the right gas and good oil, most of the world does. In fact the 32:1 ratio on your older saw is more about the quality of the oil that was sold when it was made. It would probably run fine on 50:1 with a modern oil mix.

But I run all my 2 strokes at 32:1 and haven't had any oil related issues.
Weekend warrior, Peterson JP test pilot, Dolmar 7900 and Stihl MS310 saws and  the usual collection of power tools :)

Offline woodsdog2015

  • Full Member x2
  • ***
  • Posts: 172
  • Location: Western New York
  • Gender: Male
  • Newbie Woodcutter
    • Share Post
Re: fuel mixture
« Reply #3 on: December 14, 2015, 10:48:40 PM »
Thanks
I'd rather be in the woods.
MS362CM
MS251
CS-300
Homelite 8800
FiskarsX27

Offline thecfarm

  • Senior Member x2
  • *****
  • Posts: 29309
  • Age: 58
  • Location: Chesterville,Maine
  • Gender: Male
  • If I don't do it,it don't get done
    • Share Post
Re: fuel mixture
« Reply #4 on: December 15, 2015, 06:10:34 AM »
I run 40:1 in all my saws. I have a husky 372 and a small Efco. The 372 I've had for 10 years,maybe 12. I also run the highest grade of gas that I can get at my local gas station. I have no way to turn back the clock and try 50:1 for 10 years and see if there is a diffeance or not.
Model 6020-20hp Manual Thomas bandsaw,TC40A 4wd 40 hp New Holland tractor, 450 Norse Winch, Heatmor 400 OWB,YCC 1978-79

Offline 49er

  • Full Member x2
  • ***
  • Posts: 249
  • Age: 70
  • Location: Milltown Indiana
  • Gender: Male
  • I'm new!
    • Share Post
Re: fuel mixture
« Reply #5 on: December 15, 2015, 10:10:30 AM »
AVgas or non ethanol gas @32:1 for me. No plug fouling. IMO more oil saves the bottom end.
However,like Jiles said, change your mix or gas and ya have to retune. Big difference between AV-gas and pump gas even at the same oil ratio.
Husqvarna EC390 365xt
Jonsered 2188 2165 2260 2253 70e
Redmax GZ4000

Offline Jiles

  • Full Member x2
  • ***
  • Posts: 135
  • Age: 74
  • Location: Florence Alabama
  • Gender: Male
  • Here to Learn and maybe Teach
    • Share Post
Re: fuel mixture
« Reply #6 on: December 15, 2015, 10:32:08 AM »
All my two stroke equipment has been modified. When one starts acting up, I dump and change the gas.
I do this even though other items run fine on that gas out of same container?? For some reason this happens occasionally and I have no explanation--its just  the way they are--- LOL
I have worked on MANY saws/blowers/trimmers that had nothing wrong except that the owner got on the carb. adjustment screws, and didn't change their gas.
Some people are in disagreement with me, and that's OK with me. I personally see no need for periodic carb adjustment on any engine. Carburetors don't get out of adjustment, they get restricted, damaged, or have air leaks somewhere. Many times, adjustment only mask a problem and may run better for a while.
Satisfy needs before desires

Offline HolmenTree

  • Senior Member x2
  • *****
  • Posts: 4173
  • Age: 62
  • Location: Manitoba
  • Gender: Male
  • "Been there, done that........and still learning"
    • Share Post
Re: fuel mixture
« Reply #7 on: December 15, 2015, 12:08:47 PM »
Back in the day when working 8 hr a day with the old saws with carbs mounted solidly to the cylinder and intake manifold block, the vibration of the saw would gradually turn the H L carb screws out. Never in but out and richen up. I always carried a carb adjustment screw driver in my pocket to reset the carb every few days or so.
New saws today definitely have a better anti vibe setup in the intake manifolds avoiding this condition.

Yes the 50:1 mix ratio is a EPA standard but with todays full synthetic oil Stihl sells and the semi synthetic Husqvarna sells you can't go wrong. But you'll notice on the back of those bottles they recommend either 32:1, 40:1 or 50:1. I have always run the middle ground ratio 40:1 

Making a living with a saw since age 16.

Offline woodsdog2015

  • Full Member x2
  • ***
  • Posts: 172
  • Location: Western New York
  • Gender: Male
  • Newbie Woodcutter
    • Share Post
Re: fuel mixture
« Reply #8 on: December 15, 2015, 03:59:12 PM »
Good to know and this doesn't void warranty then either right?
I'd rather be in the woods.
MS362CM
MS251
CS-300
Homelite 8800
FiskarsX27

Offline old2stroke

  • Full Member
  • **
  • Posts: 55
  • Age: 78
  • Location: ottawa, ontario canada
  • Gender: Male
    • Share Post
Re: fuel mixture
« Reply #9 on: December 15, 2015, 04:26:34 PM »
All oils are not created equal.  Some are meant for lower power density engines like 2-stroke lawnmowers (if you can find any) and other are meant for water cooled engines like outboard motors where the cylinder head temperatures don't get too severe.  Modern chainsaws put out a LOT of power and often run at full throttle for long periods and they get very hot. They require the best SYNTHETIC oils that are meant for motocross bikes, snowmobiles and racing gokarts and they need to be mixed ACCURATELY.  These oils burn very clean and won't foul plugs with a 30:1 mix or even richer.  If you are fouling plugs, the air/fuel mix is probably too rich for the operating conditions or you have a sparkplug that is way too cold.  For normal use, I don't go leaner than 35:1 but If you are using a lumber mill or cutting up  4' dia. trees  when it is 95deg F in the shade, maybe even richer.   
Not too many saws.  Not enough storage space.

Offline CR888

  • Full Member x2
  • ***
  • Posts: 138
  • I'm new!
    • Share Post
Re: fuel mixture
« Reply #10 on: December 15, 2015, 05:11:55 PM »
BMEP's are not that high in chainsaws compared to other high output two strokes. They do NOT require the best synthetic motorcycle oils that are diester/ester based at all. Still only put synthetic oil into their lineup when they wanted to keep valves in four mix engines clean. For many years fb rated mineral oil has been and still is their spec oil. Heavy bike oils designed for very different conditions to what a chainsaw will ever see. Synthetic oil was originally designed for its heat resistance properties, (not its lubricating ones) for the use in aircraft turbines as they evolved and got much hotter. A good mineral fb rated oil will not cause tuning issues and will happily keep your chainsaw in service for many years as it has done for decades. FWIW, if l was to use ester based oil in worksaws, each year the additional cost is enough to replace the whole saw brand new. Lots of misinformation on this subject, people loose rational thought when making oil choices.

Offline HolmenTree

  • Senior Member x2
  • *****
  • Posts: 4173
  • Age: 62
  • Location: Manitoba
  • Gender: Male
  • "Been there, done that........and still learning"
    • Share Post
Re: fuel mixture
« Reply #11 on: December 15, 2015, 08:07:22 PM »
I have two stihls and an echo too and the owners manuals all recommend 50:1.  Does it void the Stihl warranty to run a mixture with a little more oil? Does it protect the components better?  What are your recommendations????
As I said earlier on the back of the Stihl Ultra full synthetic oil bottle it has instructions for mixing 32:1, 40:1, 50:1.
Stihl claim to extend their saws warranty if this oil is used.
Making a living with a saw since age 16.

Offline Texas-Jim

  • Full Member x2
  • ***
  • Posts: 244
  • Age: 62
  • Location: Texas
  • Gender: Male
  • I'm new!
    • Share Post
Re: fuel mixture
« Reply #12 on: December 15, 2015, 08:53:36 PM »
Any additional fluids taken in with the fuel air mix can serve to reduce the amount of volume taken up by fuel, therefore making the engine run lean. So if you do not re jet the carb that extra oil is doing  more harm than good. And no adjusting the carb wont really help, you can turn that screw till your bored but it wont alter the jets size. Oil molecules are huge compared to gasoline, the heavier the oil mix the larger the jet has to be.

There is always a 'factory' mix ratio given for all two stroke motors. its there for a reason. the motor is designed to operate at this ratio. in any motor, 2 or 4 stroke, lessoning the fuel will cause lean burn. even though oil burns, it is in 2 strokes as a lubricant, not a fuel.
What we do in life echoes through eternity.

Offline tyb525

  • Senior Member x2
  • *****
  • Posts: 3368
  • Age: 28
  • Location: Eastern Indiana
  • Gender: Male
  • Always learning.
    • Share Post
Re: fuel mixture
« Reply #13 on: December 15, 2015, 09:37:06 PM »
This seems to be a controversial topic that I have seen come up numerous times. A google search came up with some good results. Here is one link in particular, while it references 2 stroke dirtbikes, helped me understand a little better I think.

http://www.off-road.com/dirtbike/tech/twostroke-fuel-ratios-premix-myth-vs-reality-54169.html
An interesting qoute:

"A second test they performed was to run synthetic in two identical engines and one was run at 24:1, the other was run at 50:1 The engine that ran 24:1 had less piston skirt wear, and less rod bearing wear, but had the same main roller bearing wear as the engine run at 50:1."


After doing some reading, I think I have changed my stance, it now makes more sense that more oil=leaner burn if the carb is not jetted for it.
LT10G10, Stihl 038 Magnum, many woodworking tools. Currently a farm service applicator, trying to find time to saw!

Offline Al_Smith

  • Senior Member x2
  • *****
  • Posts: 10258
  • Location: Northwestern Ohio in the center of a giant corn field
  • Gender: Male
    • Share Post
Re: fuel mixture
« Reply #14 on: December 15, 2015, 09:40:51 PM »
Oh goody the oil wars once again 8)

Offline Al_Smith

  • Senior Member x2
  • *****
  • Posts: 10258
  • Location: Northwestern Ohio in the center of a giant corn field
  • Gender: Male
    • Share Post
Re: fuel mixture
« Reply #15 on: December 15, 2015, 09:53:27 PM »
Here we go sports fans let me fan the flames a bit to get things rolling .

If 32 to one ratio fouls plugs how does one explain how old outboard boat motors ran on 16 to one .The only time they fouled was at trolling speeds .Then again nobody I know trolls with a chainsaw.

Lean burn has nothing to do with oil ratio .It's fuel to air ratio .If oil thins the mixture then logic says leaner oil ratios  should be zero oil, straight gasoline .How come nobody does that ?

I'm a 32 to one man .Just to show my hearts in right place I do have a 2 gallon can in the shed mixed at 40 to one with Stihl ultra .Simple explanation I ran out of saw gas and didn't feel like doing all that measuring .

Offline sawguy21

  • Senior Member x2
  • *****
  • Posts: 10384
  • Age: 71
  • Location: Enderby B.C. Canada
  • Gender: Male
    • Share Post
Re: fuel mixture
« Reply #16 on: December 15, 2015, 10:14:26 PM »
If 32 to one ratio fouls plugs how does one explain how old outboard boat motors ran on 16 to one .The only time they fouled was at trolling speeds .Then again nobody I know trolls with a chainsaw.
That was with ordinary 30W, all we had at the time. If a modern two stroke oil is mixed that way a white goop of water and unburned oil that looks like Lubriplate grease spews into the lake. An acquaintance who is very much stuck in the 50's still insists on doing it.
old age and treachery will always overcome youth and enthusiasm

Offline tyb525

  • Senior Member x2
  • *****
  • Posts: 3368
  • Age: 28
  • Location: Eastern Indiana
  • Gender: Male
  • Always learning.
    • Share Post
Re: fuel mixture
« Reply #17 on: December 15, 2015, 10:29:25 PM »
Al I think the logic is, say you run 20:1 in a saw tuned for 50:1. There is a higher volume of oil and less gas, but the same amount of air, which is theory makes the mixture leaner. More oil=less room for gas in the mix, while the amount of air stays the same (in theory). I definitely wouldn't say I'm a diehard supporter of the theory, but it makes more sense to me now than it used to.

That being said, I can also see the reasoning behind more oil=better because of more lubrication. And it makes sense that older 2-stroke ran 16:1 or whatever and were perfectly fine.

I think the whole thing boils down to having your motor tuned for the mixture you are running, like don't run 20:1 in a motor tuned for 100:1.

Personally I run 50:1, I use the small bottles made for 2.5 gal gas, cause I'm too lazy to measure.
LT10G10, Stihl 038 Magnum, many woodworking tools. Currently a farm service applicator, trying to find time to saw!

Offline Al_Smith

  • Senior Member x2
  • *****
  • Posts: 10258
  • Location: Northwestern Ohio in the center of a giant corn field
  • Gender: Male
    • Share Post
Re: fuel mixture
« Reply #18 on: December 16, 2015, 05:45:21 AM »

 

I think the whole thing boils down to having your motor tuned for the mixture you are running, like don't run 20:1 in a motor tuned for 100:1.

 
About the only people I know who would use 100/1 ratio work for the company that touts that stuff .That aside tuning is the simple turn of a screw .

I don't use motor oil any more but back in the day, did .It didn't foul plugs but it did throw out a smog like fogging for mosquitos .Then again I don't know anybody who  uses a chainsaw to annoy mosquitos .---next---

Offline John Mc

  • Senior Member x2
  • *****
  • Posts: 5329
  • Age: 57
  • Location: Monkton, Vermont
  • Gender: Male
    • Share Post
Re: fuel mixture
« Reply #19 on: December 16, 2015, 04:29:04 PM »
Al I think the logic is, say you run 20:1 in a saw tuned for 50:1. There is a higher volume of oil and less gas, but the same amount of air, which is theory makes the mixture leaner.

Believe me, Al has heard all this before and understands what you are saying. The Oil Ratio Wars have raged here for years. Seems as though someone brings them up again every few months. I'm guessing some years ago, Al may have been an active participant. Now he just waits for someone to start, then winds us all up again while he watches the spectacle. You could probably get a solid month's worth of reading material if you did a search on oil ratios on this board.
If the only tool you have is a hammer, you tend to see every problem as a nail.   - Abraham Maslow


Share via delicious Share via digg Share via facebook Share via linkedin Share via pinterest Share via reddit Share via stumble Share via tumblr Share via twitter

xx
Fuel mixture for older sawsf.

Started by DaveP on Chainsaws

15 Replies
470 Views
Last post November 18, 2019, 04:33:07 PM
by gspren
xx
Fuel/Oil mixture on larger Huskys

Started by twistedtree on Chainsaws

23 Replies
4841 Views
Last post December 06, 2005, 01:11:46 AM
by twistedtree
xx
Gas Mixture Uses

Started by catvet on Forestry and Logging

6 Replies
1642 Views
Last post November 24, 2005, 08:58:11 AM
by catvet
xx
Jonsered 510 SP Gas/oil mixture

Started by bphelps38 on Chainsaws

7 Replies
12450 Views
Last post May 07, 2007, 09:04:18 PM
by Corley5
 


Powered by EzPortal