n7tb

My first OS 46FX has always had one perculiar problem that none of my other OS 46FX engines have, and I was hoping someone could give me a suggestion for fixing it.

If I have fuel that is fresh, the engine will run fine. If the fuel sits for a week or so in a metal fuel container or plastic jug, the engine will start fine and run fine on the first tank of fuel. On the second one, it will start fine and rev fine, but when I takeoff, after about 5-10 seconds, the engine dies. Castor or synthetic fuel does not make any difference. I use 15 percent nitro fuel.

None of my other OS engines seem to have any problems with fuel age, and I don't think that very much moisture is getting into the fuel. I think the engine's low speed idle and high speed needle valve are set fine, but I could be mistaken.

The last time I flew the plane it was on floats and had to go retrieve it on the lake when the engine quit. I sure would like to get to the source of the problem. It is becoming very frustrating!

Any ideas?

Thanks,

Terry

Six-Shtr

My Feedback: (12)

I have two OS .61's that did the same sort of thing....replaced the glow plugs and now do a hot "run-up" before taking off. Seems to have cured my problem.

Bax

My Feedback: (11)

Please check to make sure the clunk isn't too close to the rear of the tank. A fuel surge during takeoff can cause problems.

Also, make sure you're not getting leaning from vibration-induced fuel foaming. When a model leaves the ground, its vibration mode changes a bit, and foaming can occur.