OK, I'm fairly new to the hobby and have an OS .40 FP that has very few hours on it. It ran great for about 30 flights at the end of last year. I fired it up this year and have had nothing but problems. First flight this year went great, no problems. Second flight the engine died in the air, same thing on the next flight. I have had a couple of guys at the field help me, but the problem of the engine quiting keeps coming back.

Engine starts fine, and I can tun it up, then back to idle then back up for a while, then back to idle, then back up and when it gets up to full RPM it just quits. Dead, like someone pulled the plug. Using a good quality 10% fuel left over from last year, and a 10 x 6 prop.

Any advice?

Kman

Check all your fuel lines, give everything a good cleaning, replace the plug and try fresh fuel. Its likely to be a fuel problem. Even if its been sealed, Ive read sunlight can break down the nitro in it.

I'll second that ! It had the same thing bought a new motor and same thing, change the fuel to a new container and no problem. You get this kind of reports this time of the year when flying season starts. with bad fuel. could be something eles but try this first.

roltech

IMHO ,now the engine is fairly broken in , try leaning out the high speed needle 1/4 turns until satisfied or when doing nose up test the rpm increases slightly.

Good Luck

Thanks for the suggestions, next trip to the field, it's new fuel for this engine, then if that doesn't work, Ill try a new glow plug. I'm also going to check over the fuel system, lines, tank and all that.

Kman

What you're experiencing is normal. Starting an engine for the first time in a new flying season will require some re-adjustments. Some engines will have to be re-tuned every session at the field while others seem happy with one constant setting.

In regard to your Max, it doesn't sound like you're tuning the engine properly. Set the needle valve for maximum RPM and then back it out 15-30 degrees. While other engines will run fine with a lean setting, OS engines will not run reliably tuned for maximum RPMs. Your prop and fuel are OK.

Ciao,

Eagle Al