A V gas in 2 cycle engines?

We are switching from regular gas to AV gas at our local fire station / EMS for all small engines.

I never gave it a thought to ask if it is ok to use it in two cycle, engines. I just assumed.

Also our rescue / drowning boat has a Merc 90 HP outboard on it, same question. I'm 99% sure, but again perhaps some one could put some light on this subject. I want to make sure I do not cause some issues.

Thasnks in advance. North East Iowa

I have used it in my two stroke motorcycles without any known ill effect.

Problem in Iowa, Wisconsin and Minnesota among many states is the wide use of E10 ethanol blends that mess many 2 strokes and older 4 stroke engines. Aviation gas 100 octane LL( Low Lead) does NOT have the ethanol that fouls carbs, eats diaphrams and seals. Use of the clean fuel helps reliability of small engines. Legally valid use as the small engines are not used on road and no other laws restricting its use like California. Av gas has a longer shelf life also, can sit in generator tank 6 months and be usable compared to the 2 to 3 months E10 blends get before trouble starts- often in volatile fractions needed for quick start getting lost or locked in against OH radical in the Ethanol. Good choice on fuel for a emergancy response outfit, contracting fuel would keep cost down a bit. RN

I think you are blowing smoke when you knock ethanol i use it in all may gas burners have for 15 years or more us in chain saw, ice auger, briggs on rotor tiller, town car two chev pickups one f800 ford grain truck. i never drain any 2 strocks engines. when i need them i just crank them and go to work only problem i ever had was 1975 chev 4 barrel carb float sank after about 5 years wilh ethanol put in copper float no more problems

I'm not positive but I think a similar question was asked in one of the bigger motocross(Motocross Action) magazines. I'm pretty sure they advised against it because AV gas uses different additives than pump gas or race fuel. Asking a magazine on boats or small engines might give you the best answer. Dave

E10 is blamed for a few things - like the 1982/83 Nissan fuel injector castings leaking, 1985-87 Ford fuel injector seals rotting, My Goldwing fuel pump ruined, carbs needing rebuild with a couple new material seals. 1990 or thereabout vehicles sold here were supposed to be able to use E10, prior to that was possible problems- Harley says prior to 1987 or so for start using E10. The small engine shops around here in Madison have a lot of business fixing the E10 problems in weedeaters, snow blowers, chainsaws, outboards - local bulletins warning of E10 problems for some brands and years posted on shop walls- Farm and Fleet small engine dept has copies posted for customers to read next to work orders and warantee policy. Auto parts store has fuel pump catalogs noting E10 replacement pump numbers for some vehicles- the OEM replacements are marked not waranteed for E10 use while the E10 certified units are. I was involved a bit as driver for the Cenex E10 tests in late 1970s- warnings of fouled filters in GM definite and experienced. Av gas may not be best choice but beats E10 for 2 stroke small engine equipment running steady. Alternative now around Madison is the straight premium gas- recommended by some of the new equipment makers and strongly advised for all the older engines not specified as E10 capable. The old engines are out of warantee now but some of the makers don"t like bad reputation given them by use of unrecommended fuel. Couple 2 stroke oils noted designed to be used with E10- I think Amsoil has a product and Stihl has a part number oil specified for use with E10 mix"s. RN

The stuff stores well and burns clean. Has to or it wouldn't be sold for use in airplanes.
Really annoys the people in an airplane when the engine unexpectantly quits.

Makes our snowmachines really scream! Hoss

buickanddeere

Just remember,if you are flying in a twin engine airplane and one engine goes out dont worry. The other engine will get you to the crash site.

steveormary

Kinda makes me wonder if it is more of a water in the fuel problem since the E10 should absorb more ?

I knew a person who used to work at a filling station in the 80's ? and he said boss would have them stick the tank and have some chemical on the stick to test for water and if it wasn't enough he would have them stick the water hose in the tank to water it down more !

I once worked on a 1978 buick that would hesitate and couldn't get it to go right. Finally took it to a local mechanic and he put a sample of the gas in a jar and held it up and sure enough it had just enough water in it to cause a problem but it still ran good once going.

Sounds like a bad case of histrionics in the Madison wi area

I used to work for a tree service clearing powerline ROW's. We used nothing but Av gas (100LL) in all of our saws. We used many gallons a day and never had an issue. We used it because it had a longer shelf life, didn't have moisture problems, and didn't affect rubber components.

Ignoring the lead content for a moment, the main other difference between avgas and mogas is that avgas has a much lower vapor pressure. That's necessary to prevent vapor lock at high altitude. A side effect of the lower vapor pressure is that it has a much longer shelf life than mogas. I imagine the long shelf life is why your fire department is using it in their small engines.

Now as far as the lead goes, the so-called "low lead" avgas has a LOT of lead in it. It's called "low lead" only because it has less lead than the aviation fuels that it replaced. Newer engines are designed to run unleaded fuel, which is not to say that they won't run just fine on avgas, but you probably won't get the manufacturer's blessing to do so.

but you probably won't get the manufacturer's blessing to do so.

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Our Stihl rep was glad we used Av gas, he said there is much less chance rubber failure or moisture issues.