hulio516

What is making my OS 91 FX engine "cackle" even at full throttle? Would it be the high end, low end, replace glow plug or what? I am running a 13-8 prop on it.

I'd like some possible answers please.

thank you

Edited...I moved this to the beginner section...maybe someone in there can tell me. I'm in a hurry.

Bax

My Feedback: (11)

We'd not know what you mean by "cackle".  Describing a sound in words is difficult.  If the engine is breaking-up in tone, it may be too rich, the muffler may be making a noise, you may be getting detonation from an over-lean condition or overheating.  An over-lean condition can be caused by dirt in the fuel system, a bad needle setting, vibration-induced fuel foaming, and so on.  Overheating can be caused by bad airflow through the fins of the engine, a fuel with a too-low oil content, too much propeller load, and so on.

Your best bet is to put the engine on a test stand and run it there.  If it's fine on the stand, then the problem lies with the engine/airframe/fuel system combination, and will require some detective work.

hulio516

I solved the problem.....

All I had to do was replace the glow plug. Even though I only had about 3 flights on the new original plug I was using, for some reasonthat plugwent bad. I guess I was puzzled in the beginning since it was a new plug with only 3 flights on it.

Easy fix!

thanks for replying Bax