Fuel and alcohol

[Robert M. Gary]

We've been talking about the dangers of running MOGAS that containa
alcohol I thought this was interesting. I bought a new weed eater a few
months ago and let it sit for a few months. Now it will not start and
the shop is saying the alcohol they are putting in mogas nowadays is
cloging up the fuel lines and the carbs. They are recommended keeping
weed eater gas for no more than 30 days and to run the engine dry
before shutting down. If it does so much damage to weed eaters I'd hate
to think what could happen if you put it in airplanes.

-Robert

[Peter Duniho]

"Robert M. Gary" > wrote in message
oups.com...
> [...] They are recommended keeping
> weed eater gas for no more than 30 days and to run the engine dry
> before shutting down. If it does so much damage to weed eaters I'd hate
> to think what could happen if you put it in airplanes.

30 days may be overly conservative, but that advice is valid whether or not
there is alcohol in the gas. Regular auto gas isn't as stablized as
aviation fuel, and degrades faster. As the volatile components evaporate,
you're left with a gummy residue that clogs all sorts of things.

Running the carburetor, if not the fuel tank, dry before storing for any
significant period of time is standard operating procedure for stuff with
small gas engines in it (leaf blowers, lawnmowers, weed cutters, chainsaws,
etc.)

Pete

[Stubby]

I was advised to add "stabilizer" to my mower gas. It doesn't seem to
fart and cough as much now. I plan to seek out ethanol-free gas so I
don't have to run it dry which lets the diaphragm and gaskets crack.


Robert M. Gary wrote:
> We've been talking about the dangers of running MOGAS that containa
> alcohol I thought this was interesting. I bought a new weed eater a few
> months ago and let it sit for a few months. Now it will not start and
> the shop is saying the alcohol they are putting in mogas nowadays is
> cloging up the fuel lines and the carbs. They are recommended keeping
> weed eater gas for no more than 30 days and to run the engine dry
> before shutting down. If it does so much damage to weed eaters I'd hate
> to think what could happen if you put it in airplanes.
>
> -Robert
>

[Steve Foley[_1_]]

What would 100LL do to a lawn mower?

If the answer is foul the plug, I'd rather clean a plug than screw around
with gunked up fuel lines.

"Stubby" > wrote in message
...
> I was advised to add "stabilizer" to my mower gas. It doesn't seem to
> fart and cough as much now. I plan to seek out ethanol-free gas so I
> don't have to run it dry which lets the diaphragm and gaskets crack.
>
>
> Robert M. Gary wrote:
> > We've been talking about the dangers of running MOGAS that containa
> > alcohol I thought this was interesting. I bought a new weed eater a few
> > months ago and let it sit for a few months. Now it will not start and
> > the shop is saying the alcohol they are putting in mogas nowadays is
> > cloging up the fuel lines and the carbs. They are recommended keeping
> > weed eater gas for no more than 30 days and to run the engine dry
> > before shutting down. If it does so much damage to weed eaters I'd hate
> > to think what could happen if you put it in airplanes.
> >
> > -Robert
> >

[ktbr]

Steve Foley wrote:
> What would 100LL do to a lawn mower?
>
> If the answer is foul the plug, I'd rather clean a plug than screw around
> with gunked up fuel lines.

I use it in my lawn tractor now and again. It actually makes
the thing run better. With the drought lately I haven't had
to run it as much and the mogas putrifies so quickly that
I've taken to using the Avgas... suprised by how much nicer
it runs, of course I may have to clean the plug eventually.

[Steve Foley[_1_]]

"ktbr" > wrote in message
...
> Steve Foley wrote:
> > What would 100LL do to a lawn mower?
> >
> > If the answer is foul the plug, I'd rather clean a plug than screw
around
> > with gunked up fuel lines.
>
> I use it in my lawn tractor now and again. It actually makes
> the thing run better. With the drought lately I haven't had
> to run it as much and the mogas putrifies so quickly that
> I've taken to using the Avgas... suprised by how much nicer
> it runs, of course I may have to clean the plug eventually.

I'd be willing to bet that the lawn mower at my airport has been fed a
steady diet of 100LL since it showed up.

[nrp]

ktbr wrote:
> Steve Foley wrote:
> > What would 100LL do to a lawn mower?

100LL left in a carb bowl will lose fewer of the lighter hydrocarbon
components to evaporation than will autofuel etc. Starting difficulty
in any carburated engine is commonly related to fuel vaporization
problems, so you may find that 100LL actually makes them easier to
start. In addition 100LL will run richer than will autofuel so a
smoother running engine may result if the as-manufactured mixture
setting is marginally lean.

However, autofuel will start much better if you can run the carb bowl
empty on shutdown & refill it with fresh fuel immediately before
starting. I do that on my 172M if it is going to sit for more than a
few days.

The seal compatibility issue makes a wonderful excuse, but this thing
is possibly overblown as viton seals, which look and feel like
neoprene, are impervious to most anything at only a minor cost premium
for industrial applications. Obviously if the "seals" are static or
metal-to-metal and there is no corrosion, the seal material shouldn't
matter that much unless of course there is the problem of certification
of antique technology.

The reduction in power and corrosion issues of E10 or higher fuels
though is a real issue though. I wouldn't use it, and I wouldn't want
to experiment with my own fuel hooch either.

[Robert M. Gary]

The funny thing is that weedeaters seem so prone to this, yet I'll let
my lawn mower sit for an entire season with fuel in it and it always
starts on the first pull. Never any problems, hot start, cold start,
etc. However, the weedeater is very, very sensitive to anything when it
comes to starting.

-Robert

Peter Duniho wrote:

> 30 days may be overly conservative, but that advice is valid whether or not
> there is alcohol in the gas. Regular auto gas isn't as stablized as
> aviation fuel, and degrades faster. As the volatile components evaporate,
> you're left with a gummy residue that clogs all sorts of things.

[Peter Duniho]

"Robert M. Gary" > wrote in message
oups.com...
> The funny thing is that weedeaters seem so prone to this, yet I'll let
> my lawn mower sit for an entire season with fuel in it and it always
> starts on the first pull. Never any problems, hot start, cold start,
> etc. However, the weedeater is very, very sensitive to anything when it
> comes to starting.

My experience has been that the smaller the engine, the more susceptible it
is. Also, the two-stroke engines seem to me to be worse than the
four-strokes, possibly because the fuel has oil mixed in and so has more
stuff left over to gum things up after the volatile fuel components
evaporate (I don't know if your weed cutter engine is a two-stroke, but it's
a good guess that it is, while likewise most lawnmowers have four-stroke
engines). Or possibly just because they are generally smaller engines.

I have had trouble getting a four-stroke engine started after a long
storage, with some rough running initially, but eventually things smooth
out. It's only been with a two-stroke engine that I've had to get the thing
serviced, it got so gummed up after sitting too long.

The fuel stability issue may well be something to watch with an airplane,
especially one that doesn't fly often. I haven't heard of it causing huge
problems, but that doesn't mean it doesn't happen. Still, my main point is
that I doubt that it's the alcohol in the fuel that is responsible for the
"so much damage" the original poster was talking about...more likely, it's
just letting any fuel sit around too long, alcohol or not.

Pete

[Bob Noel]

In article >,
"Peter Duniho" > wrote:

> My experience has been that the smaller the engine, the more susceptible it
> is. Also, the two-stroke engines seem to me to be worse than the
> four-strokes, possibly because the fuel has oil mixed in and so has more
> stuff left over to gum things up after the volatile fuel components
> evaporate (I don't know if your weed cutter engine is a two-stroke, but it's
> a good guess that it is, while likewise most lawnmowers have four-stroke
> engines). Or possibly just because they are generally smaller engines.

I've had a different experience. Each of my lawnmowers and the weedeater
have been fine. The toro snowblower doesn't like being stored without being
prepped. My 250cc Honda motorcycle took the winter without a hiccup.
My 750cc Honda was a pita to start after the winter even with the prepping.

--
Bob Noel
Looking for a sig the
lawyers will hate