too much alcohol in the gas.

[Sawyerfortyish]

I don't know if any of you guys look but it tells you on the pump how much alcohol is in the gas. Right now 2 of my saws have the diaphram in the carb eaten up by too much alcohol. I have a friend that is a stihl technician and he told me it's become a huge problem. Not long ago he had to go to Massachusetts to find out why 9 landscapers in one area had blown up so much of there two stroke equipment. His findings was that all of them had bought gas from the same station. So he tested the gas to find out that it was 26% alcohol way to much for small engines. From what I'm being told this is going to only get worse. He suggested mixing less gas with the same amount of oil I normaly use and don't buy the cheapest gas I can find as that seems to be mixed with more alcohol to bring the price down and the more expensive gas has less alcohol.

[leweee]

  seems to be a two fold problem.cheap gas & cheap neoprene.

They just don't make either like they used to.

[Dave Shepard]

I have a friend that is having a terrible time with his two stroke stuff. Only brand affected is Shindaiwa. We have been running Shin equipment for almost ten years, since the introduction of alcohol blend, they aren't lasting at all. I don't know if it is related. I have been told theat the alcohol will settle out of the gas, leading to a lean condition. I don't know if that is true, does anyone have any experience with this? I almost lost a saw this spring to bad gas, but I caught it quick enough.


Dave

[PB Logging]

I've had a great deal of problems with fuel. Lean seizures, etc,.  We consue about 15 gallons of mix a week.  There is a similar discusion thread that was started some time ago.  I suggesst looking it up as it contained a fair amount of info.

[Timburr]

The general consensus for alcohol in fuel is:-

1.  Rubber degradation in carbs and fuel lines.
2.  Aluminium is slightly soluble in alcohol.  In the long term, this is undesirable on a small two-stroke.
3.  Alcohol is thicker than petrol (gas).  It's less efficient at "jetting", causing lean siezures.
4.  Mixes easily with water, making the fuel more corrosive.  Again, a lean siezure factor.

Some older FF threads on the subject.

How much alcohol is too much?
alcohol or no alcohol? Leaky 372 fuel cap
alcohol in fuel   

[rebocardo]

I have three "dead' lawnmowers, all B&S 6 HP, and from what I can see so far it is all clogged carbs from fuel lines that went bad. I suspect it is the alcohol in the fuel people use.

I have been running 50:1 (mostly for my Stihl), I might go back to 40:1 like I use to.

[oldsaw]

I'm considering going to 100LL.  More stable, no alcohol.

Mark

[stonebroke]

Pardon my ignorance, what is 100LL?

Stonebroke

[oldsaw]

Pardon my ignorance, what is 100LL?

Stonebroke

AVgas for small planes.  About $5/gal at your local airport.

Mark

[pineywoods]

FWIW most piston-engine aircraft run just fine on auto gas. 100LL is beginning to get scarce in some areas, so lots of small aircraft are now running autogas. Alcohol is an absolute no-no, corodes aluminum tanks and fuel lines, absorbs water which then freezes at high altitudes.could ruin your day. As a concesion to aviation, some states exempt the alcohol requirement on premium autogas. I run it in all my chainsaws and my mill.  Check your local small airport, or I may be able to find out which states are so enlightened.

[Dave Shepard]

On the pumps in my area, the 10% notice is not attributed to any one grade. I can only guess that all grades are mixed. Would I be correct in guessing that ethanol has less energy per gallon as well? I wonder how the internals of a two cycle like the alcohol, I would hate to think they are being eaten away when the saw is just sitting.


Dave

[Sawyerfortyish]

Alcohol eats the diaphram in the carb weather the saw runs or sits. Don't always believe everything you read just because it says 10% doesn't mean there can't be more than that. My friend the saw technician tested 26% at a pump.

[olyman]

and in that vein--ive run alcohol gas in the lawnboy, and chainsaws since day one---buttttttttt--i run a higher ratio of oil also--and have had no problems--the local stihl man says stihl doesnt like the alcohol and 50:1 mix--not enough oil for the "dry" alcohol---so--as has been discussed on another forum--run a higher oil ratio---

[JJackson]

Sawyer, we were told to mix as you where by our stihl dealer that services all the company saws. (more oil less gas).  We have just started to do that in the field so I can say if it's working or not.  We have always run premium gas.

[Sawyerfortyish]

I started buying a higher grade of  gas about ten years ago at the mill because the oxegenated regular gas would completly ice up the outside of the carb on my one loader and stop it from working. With the higher grade of gas it didn't ice up and was fine. I hated to spend the extra money for the better grade of gas but it beat sitting there thawing the carb out to get back to work.

[Night Raider]

100LL (avgas) works really well in 2 strokes.  I've run it a lot in outboard motors (fly in camps) and a bit in chainsaws.  I find it runs cleaner with less fouling all around, of course it is 100 octane.  It also has a rated shelf life of 3 years compared to 6 months for road gas.

[ErikC]

 I have avoided calamity in this regard by the following--
 
  1 Highest octane fuel
  2 name brand oil at a bit less than 50:1
  3 mix about 10 gallons at a time, lasts around 4-5 days
  4 add stabilizer in the wet months

I run stihl saws with stihl mix, and operate saws a lot. So far I have never had a problem with my fuel systems. My oldest saw is 11 or 12 years old, an 039. It has hundreds of hours, sits out in the weather from time to time, and so far so good. Maybe i'm just lucky,  but I think what I'm doing works.

Erik