Avgas in the snowmobile

[wagonwrench]

Howdy All, I was wondering if anyone here has ran 100ll in there sled as the main fuel during the season and kept it in there during the off season? It sure stores well....


WW

[670x]

Yep I have run a lot of avgas through my sleds. I usually mix it about 50% with pump gas 91.
It works great in the yard equipment as well.

[ajfriz]

That's all my snowmobiles have seen. My trail 90 likes it as well.

[Nosedragger]

It keeps well and is a great alternative to race fuel for some high compression engines, especially boosted four strokes without sensitive reeds. The only performance gains by running high octane fuel in stock engines can be atributed to the placebo affect. Octane is a retardant which prevents predetonation, therefore running the lowest octane you can get away with achieves the highest performance. Be prepared to clean plugs often.

[mtv]

I ran snowmachines, outboard motors and other small engines on avgas exclusively. Never had a problem.

MTV

[bumper]

I understrand that in Rotax 912's and 914's, leaded fuel cuts down the recommended TBO by half to 1000 hours, also halves the oil change interval. The lead "centrifuges out" in crank shaft oil passageways and can result in bearing problems due to oil starvation. Valve sticking can be an issue as well.

So, if the manufacturer has recommendations, I'd follow them. If not, depending on the engine, how many hours it accumulates etc . . . I'd still have concenrs running straight 100LL in my small engines if I wanted them to outlast me . . . and if ethanol free mogas was available.

[180Marty]

I'd still have concenrs running straight 100LL in my small engines if I wanted them to outlast me . . . and if ethanol free mogas was available.

Bumper, maybe you didn't see courierguy's post on his Montana trip.

I continue to be amazed at the economy of the Rotax 912S, high, hot and heavy it averaged 3.2 gallons of mo gas, including 14 gallons of 10% ethanol.

[172heavy]

One thing that never want to do is run straight synthetic automotive oil with a leaded fuel, the lead crystalizes in the oil and wears everything out, and early synthetic aircraft oils were disastrous because of this, now all synthetic aircraft oils are synthetic blends, and yes I run them in my aircraft. Otherwise I run AV100LL in all my small engines, chain saws love it!

[ajfriz]

I've never had a reliability issue running avgas in small engines. I'm pretty sure that the old Honda 90 hasn't even had the spark plug changed since about 1985 and she's still running strong

[mtv]

All the snowmachines I've been around are two stroke, so valves--ain't got no stinking valves. I realize there are now some four stroke machines out there, and they MAY be more sensitive to leaded fuel.

MTV

[Arcticmayhem]

I like to mix about 10-25% with 87 octane just for the smell and for the storage properties. It seems to run a little cleaner and haven't noticed any detrimental effects. I don't need it for the performance, as my sled is set up to run 87, but I like the smell. For the new Power-tec, E-tec, or any other sled that automatically compensates for octane, you will see a few more HP, just like running 91 (hard to get in AK) or with an octane booster. I Don't know what the long term effects might be on exhaust power valves but with the high compression engines, I would say that since they have a very complete combustion, there should be no lead left behind to gum anything up.