Prop nut problem
 

I keep having a problem with my prop nut. For some reason, no matter how tight i tighten it, or how much as my friends do, the nut always comes unscrewed and the engine dies about 5 minutes into its running.
Do i need to buy a new prop nut, and where can I get a new one?

Prop nut problem
 

It sounds like your engine is turning over, backwards. A guy in my club had the same problem. If you are using an electric starter check to make sure that it is turning COUNTER CLOCKWISE

-Dan

no no
 

its goin counter clockwise, im sure of it

Prop nut problem
 

It could be that you are running your engine too lean. This will cause the engine to backfire and loosen the nut.

It will also cause the engine to quit.

if left unchecked, it will eventually ruin the engine.

Prop nut problem
 

If your engine is to lean a way to check it is to:
1) Start it
2) Run it wide open
3) While on full throttle take and hold your plane nose up in the air. Your engine will quit if it is to lean.
To adjust your mixture you would :
4) Re-start engnie
5) Run it on wide open
6) Then adjust the needle valve usually away from you
7) Repeat steps 1-3

Prop nut problem
 

Slight modification to the above advice in bullet

3) If the engine loses RPM at all it's too lean. It doesn't have to die, just sag. You should hear a slight RPM increase when holding the plane nose-up, or maybe no change at all.

Btw, what kind of engine? older 4-stroke were known for kicking backwards and throwing props. I've also had a few brand new .40 size two strokes with prop throwing problems when they were flooded on start, they would sometimes kick.

You can also lower the compression of the engine or reduce the nitro a little, that sometimes helps.

Beleive it or not, some "long" glowplugs are longer than others. OS plugs are particuarlly short. I've now had 2 students with funky running engines that were fixed by going to a shorter plug. If I recall, one was an OS 46FX the other was a Super Tiger .36. One was, in fact, kicking backwards a lot. When flip starting it always took off backwards, so I started it running forwards by flipping it backwards. But going to a shorter plug fixed the problem.