Chainsaw Gas

[Rat Rod Mac]

Has anyone run 100 octane aviaton gas in their chainsaws. It has lead in it. I live close to a small airport and am getting tired of junk gas, so I thought I might try some av. gas, but did not want to until I checked with you guys. Any suggestions are welcomed. Thanks. RRM

 

[Mousefield]

Suggest you read your manual. I'm just guessing but probably not good for it.

 

[ultrarunner]

No... but from reading the Forums... I thought I was going to have all kinds of trouble with my "New" Stihl saw.

A little over two years ago... a large tree fell during a windstorm up in Olympia WA where I was staying. Being 800 miles from my tools and wanting a Stihl saw... I bought one and had the tree cut-up in no time...

Planned to do some more work on the weekend and then got the call that I was needed at the job... 800 miles away.

My new MS 250 C-BE saw sat the entire time in the basement with a tank full of now 2 year old gas... it started on the 4th pull and I spent the day clearing fallen trees and used the rest of the gas I had mixed 2 years before...

Maybe I was just lucky?

I used the Stihl oil the dealer had given me and the saw and fuel were stored in a cool, dry place... probably about 50 degrees year round.

 

[CWOSCSU]

You won't have any problems running AV gas. Additional benifit is all AV gas is alcohol free. Downside is cost. Are you sure it's leaded? The AV gas around here is unleaded.

 

[Rat Rod Mac]

A pilot friend said it was leaded. I will find out when I go to buy some. He said it goes for over four bucks a gallon, but for all the more I will use it would be worth it if the saw runs good. Thanks for the replies. RRM

 

[NIXON]

A pilot friend said it was leaded. I will find out when I go to buy some. He said it goes for over four bucks a gallon, but for all the more I will use it would be worth it if the saw runs good. Thanks for the replies. RRM

You're talking about 100 LL fuel . It is leaded ,but not to the extent of fuels of yesteryear .
I doubt that You'll gain anything from using it over a good premium fuel however .
But then it's Your saw , and Your $ .

 

[ultrarunner]

Premium here is going for $3.69 a gallon at the near by Shell Station... $4 a gallon doesn't sound too expensive for alcohol free fuel for the saw.

 

[Chilly807]

Get the avgas and thank your lucky stars you have the option. It's the best fuel we can get, and the lack of ethanol is a real bonus.

Chilly

 

[CWOSCSU]

Forgot to mention one thing. If you have a newer (post 2006) saw that meets emission requirements for CA, then don't use leaded fuel. These saws (and all other 2 strokes) have catalytic converters (similar to a gas engine car) and the lead will clog it pretty quickly.

I agree with the others that premium auto gas is sufficient (octane wise), but I知 get concerned with the alcohol levels. In SE PA we are seeing alcohol levels greater than 15%. High alcohol raises the cylinder temp, and can melt a piston. The Stihl dealer that I use showed me one. They have an alcohol test kit, and measured the alcohol at 26%. The saw owner had been adding drygas which caused the high alcohol level. Unknown how much was in the gas at the pump. I had them measure fresh 92 octane and it was 16%. So, I've been using marine grade Stabil (blue color) which is suppose to counteract the effects of the alcohol. I also use fully synthetic 2 stroke oil. I put about 15 hard hours a week on my portable 2 stoke equipment and haven't had any problems. So, I'm assuming what I'm doing is working.

Thanks Mike.

 

[SimS]

Mike;

Not to start a argument, but IMHO don't think alcohol, itself, melted the piston. Alcohol burns much "cooler" than gasoline. In my bike racing days you had to "jet up" to get power from alcohol. What probably happened was, as the alcohol content went up in the fuel, the oil mix ratio stayed the same. The lack of enough lube probably fried the piston through excessive friction. With alcohol in two strokes you really have to put in lube, like 30:1 or 28:1. Nothing like the sounds and smells of a two stroke on alky at full throttle.

SimS

 

[captaincrab55]

No... but from reading the Forums... I thought I was going to have all kinds of trouble with my "New" Stihl saw.

A little over two years ago... a large tree fell during a windstorm up in Olympia WA where I was staying. Being 800 miles from my tools and wanting a Stihl saw... I bought one and had the tree cut-up in no time...

Planned to do some more work on the weekend and then got the call that I was needed at the job... 800 miles away.

My new MS 250 C-BE saw sat the entire time in the basement with a tank full of now 2 year old gas... it started on the 4th pull and I spent the day clearing fallen trees and used the rest of the gas I had mixed 2 years before...

Maybe I was just lucky?

I used the Stihl oil the dealer had given me and the saw and fuel were stored in a cool, dry place... probably about 50 degrees year round.

ultrarunner, Your very Lucky to still have a working saw.... Your saw may still experience problems from that bad gas.....

 

[CWOSCSU]

Sims,

I agree. Have you had an experience with the Marine Stabil? Suppose to counteract the effects of the alcohol. Don't know of anyone who has used it, and was just curious.

Thanks, Mike.

 

[The Haymaker]

Keep the gas fresh and store in a temperature controlled space. Moisture causes trouble with the new brew, not just because it has ethanol. I run the ethanol brew in a two stroke bike, fourstrokes bikes, and chainsaw with no issues. My two and four stroke bikes had 6 month old gas in them and still started fine.

 

[ultrarunner]

ultrarunner, Your very Lucky to still have a working saw.... Your saw may still experience problems from that bad gas.....

Agreed... I was expecting the worst... it was nice to be pleasantly surprised... doesn't happen all that often.

 

[tjc1989]

Get the avgas and thank your lucky stars you have the option. It's the best fuel we can get, and the lack of ethanol is a real bonus.

Chilly

I agree. If I could get AVGAS 100LL , in a convenient fashion at $4.00 and under a gallon, I would run it in most of my smaller stuff in a heartbeat. I would run it in my motorcycle, but its not really cost effective, for it.

I run premium in my chainsaws, and weed eaters. And occasionally regular when I am out of my premium stash. Main thing is don't try to store auto gas for long periods.

 

[NIXON]

I agree. If I could get AVGAS 100LL , in a convenient fashion at $4.00 and under a gallon, I would run it in most of my smaller stuff in a heartbeat. I would run it in my motorcycle, but its not really cost effective, for it.

I run premium in my chainsaws, and weed eaters. And occasionally regular when I am out of my premium stash. Main thing is don't try to store auto gas for long periods.

Just a question here . a s You don't mind running different octane ratings , do You have to retuned ,or adjust Your carb for different fuels ?

 

[The Haymaker]

Just a question here . a s You don't mind running different octane ratings , do You have to retuned ,or adjust Your carb for different fuels ?

Most engines aren't bothered much by different octanes when it comes to jetting. In actuality, you only need to run a high enough octane to stop pinging. A good example is my offroad bike. Running high test in it actually DROPS mpg because the stock compression engine does not burn it as efficiently.

 

[tjc1989]

Just a question here . a s You don't mind running different octane ratings , do You have to retuned ,or adjust Your carb for different fuels ?

Good question. For me personally, it depends on the piece of equipment. For my 4 cycle stuff, such as my pressure washer, roto tiller, lawnmower, etc, -- No. But 2 cycle stuff, such as chainsaws and weedeaters, yes. I find that the slightest change in oil to gas ratio, age of gas, and octane of gas make a 2 cycle behave in minute differences. And I usually have to compensate a little by adjusting the carb, especially on the high RPM side. In my opinion, just the nature of the beast with 2 cycle equipment. I just accept it and go on.

I guess a word of caution, though. If I could get my hands on Avgas 100LL , I would probably run it with just about 5 % more oil to the mix to compensate and counteract any heating issues, especially with chainsaws, as they have to run wide open and harder than most other 2 cycle stuff I may have.

 

[dodge man]

This has been discussed a lot in regards to avgas in older cars. It is my understanding the avgas is a little different than other gas. The problem is I can't remeber why. It might have something to do with vapor pressures?

 

[NIXON]

Most engines aren't bothered much by different octanes when it comes to jetting. In actuality, you only need to run a high enough octane to stop pinging. A good example is my offroad bike. Running high test in it actually DROPS mpg because the stock compression engine does not burn it as efficiently.

Your comments were interesting ,and for the most part correct . I do, however ,find that My saws are sensitive to fuel quality , octane ,and oil mix . So , I try to keep everything as consistent as possible . In fact My 044 seems to be the most sensitive . I've heard it doing the frying egg sound on cheap gas once ( claimed 89 octane ) . I now stick with Shell and BP premium .