I have a magnum engine that seems to be vibrating and afraid of damaging something while in flight is it normal to have the engine vibrate excesively? and then it dies out at idle what could it be? i checked the valves with a feeler guage and its set to .004" any thoughts to this? one thing to note im using 10% fuel for breakin and my prop seems to be balanced pretty good its a master airscrew 14-6

should i switch to 15 % fuel now that it has been broken in? will it run smoother?

I have a Magnum 91 four stroke. It doesn't seem to vibrate any different than my OS and Saiot 91's.

You may have it still set on the rich side?

Higher nitro is not going to change it.

Enjoy,

Jim

10% are good enough for the Magnum 91.. you will spend more money at 15% nitro..

Jens Eirik

If you are sure your propellor is balanced correctly, then it might be something else attached to the engine. For example, are you also using a spinner? Many times, a spinner cone and/or the spinner backplate will need to be balanced as well.

it is mounted side ways will that play a part in that?

Mounted side ways runs about the same as being upright

Enjoy,

Jim

just stick you d i c k in it and then shove it up your a s s and master bate 12 times

As above, sounds like the bottom end is still set a little rich..

I had the same problem with my Magnmum .91 4-stroke, i changed glow plugs and it solved my problem.

what glowplugs did you use?