Gas damage to saw

Robert P

TreeHouser
Joined
Jul 11, 2014
Messages
275
As I understand it current pump gas with ethanol will deteriorate plastic fuel lines in power tools and you should purge them when they're going to be stored. But what about tools that are used constantly and constantly have fuel in the lines? If they're constantly exposed to ethanol are they doomed to have rotted lines eventually?
 
Most newer tools can tolerate ethanol fuels. I am fortunate that I can buy ethanol free gas and I always use 92/93 octane.
I don't know about special formed fuel lines but "tygon" fuel lines are available.
I believe Marine StaBil is supposed to neutralize ethanol in gasoline, but I have no experience.
 
Viton might be good for ethanol. It holds up great with 100% biodiesel, pricey but ya get what ya pay fer.
 
I think it depends on the compounds. I've seen a few fuel lines just literally disintegrate in homeowner saws. No problems with with the pro stuff so far. . .

I'm pulling a Stig though, and have just been running Alkylate in my personal stuff. No probs there either. . .
 
Gas is different in different areas. Ethanol is not the culpit in this drama, it is all other crap they have in it.
I talked to a guy that set up 5 new saws to run E-85 with recin oil as lubricant.
They ran them in forestry a year, pulled them down and documented everything. It was a years test, would be fun to see what happen in a longer test.

Here is a HVA fuel hose from a 266 I put in for a customer. It lasted less than a month in the saw. I doubt he ran 10 tanks of fuel in this time.
CIMG3810.JPG
The hose melted and in bottom of tank was two lumps of rubber with the filter. In carbs filters there was lumps of rubber as well.

We have really crappy fuel here compared to most others it seems. Why I am not sure but they say it is enviormentally correct.
 
Almost everyone here run Aspen fuel as this is what the manufacturers wanted us to run since early 90's.
With this there is very little fuel related issues. Now there is everal other brands of Alkylate fuels around.

A word of caution when you tinker with fuels and test different fuels and oils. Some don't do well together and can actually cause damage.
Some oils don't like some fuels and others eat up all crap inside engine left by some fuel mixes.
This can cause damages.
 
In todays world, we have two major problems. One is the ethanol and the other is inferior rubber quality. They sometimes don't work well together.
If I had to use ethanol I would always store the chainsaw dry or completely full. Alcohol absorbs moisture and that causes carburetor corrosion. More air more moisture.
 
Ethanol is not aggressive. If you have ethanol in a jar and put whatever rubber or plastic in it nothing will happen.... Almost indefinite.
With a oil that can mix with it it is not a issue.
If you have 10% Ethanol and use a oil that doesn't mix with alcohols, you are in trouble as 10% of fuel is not lubricated.
 
I decided to just use Stihl oil. Never have any problems with my saws. I leave fuel in them all year long.


When my parts man told me it was the ethanol that was ruining the parts he sells me, I decided it was the fact that he sells me the cheapest junk he can mark up the highest.
 
Ethanol is not a suitable solvent were other alcohols as methanol is.
Methanol however has been used in two stroke combustion engines (with a oil that can mix) for a very long time without complaints...

Odd isn't it?
 
Methanol is used in Indycar racing I think.

Aliphatic alcohols we use in combustion there is: Methanol, ethanol, propanol, and butanol
Interesting reading: https://en.wikipedia.org/wiki/Alcohol_fuel

It is not a aggressive substance if you compare it to other substances like Benzene in your gas.
Benzene, fat acids and other crap we are to burn in cars is what gives us issues with plastic and rubber.

Alkylate fuel is the cleanest form of petroleum with no benzene or fat acids and is what they ran engines on in beginning.
Its what 95% of the chainsaws run on here I service. Almost no fuel related issues unless they get confused and use other fuels.
 
I'm not sure if ethanol does any permanent damage .Given enough time it will damage soft components of carbs and crankshaft seals .

Some of the last repairs I made on Stihl products it looks like they've changed the formulation of the seal as they are blueish in color and some of the newer carb rebuild kits have different components there in than older stuff .I'm assuming these are more robust than older stuff .

Where I live in Ohio we are pretty much stuck with ethanol type gasoline .The only other option would be race fuel ,aviation gasoline or drive 90 miles to lake Erie and buy marine gas .I'm not going to do it period .If it were a 1936 Harley knuckle head or a 1927 Rolls/Royce yes but it just a chainsaw .So you just replace things every so often .
 
Ethanol fuel (E85) doesn't give damage to rubber components when run a year in saw.
Not fuel lines, seals, membranes or anything. The pistons looked like new, engine had no carbonized fuel or oil residue in it after a year of use.
I think that explains quite a bit.

From memory they had no motor issues at all running it. Other than it needed about 25% more fuel and was hard to start when it was under -15c there was no issues at all if I remember correct.

Here there is minimum 10% and up to 25% in some cases in gas stations..
 
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