Hi there
Can anyone tell me the best fuel % for using in my sc .46 two stroke eninge im running it on rich nitro truck fuel and am gettin an oil residue and no smoke? Is this normal? any help would be great thanks

stop using that car fuel asap,it doesn't have enough oil in it.when i flew i.c. i found my sc engines ran best on duraglo 10%.

Use any good fuel with some nitro, I use S&W 15% nitro with 20% oil blend. The blend usually consists of some synthetic oil with some castor content. The oil content is what is important. You can adjust the nitro content based on availability in the UK and how you want the engine to perform. Generally, 15% nitro will give you good starting and good tuning ranges. We pay about 15 US Dollars here for a gallon of fuel (hey.. guys... don't sweat the small stuff. That is just an average or estimate cost for fuel.. so don't get your feathers all ruffled up over a dollar or two in that estimate).

Like it or not Airplane engines are different from car engines, or at least we treat them differently.

Glow AC engines always work best with 18-20% caster oil blended with 5-15% nitro. The amount of nitro depends on the engine specifications - if you are flying FAI standards, it is 0% Nitro.

Back to basics, these 2 stroke engines get hot! They require cooling and lubrication or they seize up! [X(][:'(]

Get the correct fuel, retune the engine and have fun!

Car engines seldom hold full throttle for as long as we are WOT with our airplanes. They're also backed off a lot. Backing off the throttle cuts the heat input a lot. We don't do that "going into every turn" either.

So use any popular airplane fuel and you'll be ok.

Don't worry about nitro, as almost none of our airplanes actually benefit from more nitro than 5% or 10%. So save your money and use low nitro. Most people can't tell the difference. Because there really isn't much. Low nitro fuels save you money when you buy. And there is a slight benefit in gas mileage too. And engines last longer and are less apt to be screwed with a bad needle setting. For the average flyer who isn't flying pylon or precision aerobatics, more nitro than 15% is usually a waste of money. But beauty is in the eye of the beholder. So if you think a little more scream from the engine is worth it, have at it. Lots of room in this hobby for whatever trips yo' trigger.

if you belong to a club, they might have some fuel for sale, my club buys 50 gallons at a time and sells it for $12 a gallon and it's %15