RCU Forums - Prop keeps falling off

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RE: Prop keeps falling off

Quote:

ORIGINAL: brett65

Quote:

ORIGINAL: turdfergerson

Quote:

ORIGINAL: Gray Beard

Turdfergerson, What is it about not priming my engine before hitting it with my starter that would cause me problems with my prop falling off??

Like someone mentioned in another post, trying to turn a dry motor can create friction, making vibration that will cause the nut to back itself off. I had the same prob when I was first getting started in this hobby. before you apply the electric starter hold your finger over the exhaust outlet and turn the prop counter clockwise. wait until you can see fuel pass through the needle valve and up to the carb. then apply the glow stick and then the starter. if you find yourself turning the engine for more than five seconds remove the glow stick and reprime. it should only take a quick turn of the starter and she should fire up. good luck man.

A better way to prime is to open the carb to full throttle and put your finger over the inlet. The fuel will come into the carb with only 1 turn of the prop in most cases.

good to know, thanks for the info.

RE: Prop keeps falling off

Another thing to keep in mind... A closed carb will let the engine spin easier/faster due to limiting compression. Start your engine with the carb closed and then open it slightly once it's spinning. This is with an electric starter
Mike

RE: Prop keeps falling off

This is what OS engines sent me when i asked for a torque spec. for my 55 ax.

Thank you for your recent e-mail. OS dose not give any torque specs at all. Our techs that repair them say to use a 6 inch crescent wrench and tighten them as tight as you can.

RE: Prop keeps falling off

Man rod bolts on a car, truck or such tighten down from 45ft lbs. to 90ftl lbs. depending on vehichle. A SBC tightens at 75lbs. head bolts 90.
Props are tighten until you think your going to break something and then about a 1.4 turn lol. A backup nut will also help keep the nuts from coming lose. Had a wood prop that looked and felt tight but would scream at open throttle sounded like the motor was blowing up and rods coming loose. But ended up being just a turn or 1/2 turn from tight enough.

RE: Prop keeps falling off

Try putting another nut on it and use less time with the starter.