Hey guys after soloing on my avistar a while back the second to last flight I broke the wooden prop that came with my avistar. Now I put on a master airscrew prop of the right size. Ohk startup........... clicketyy clank clicketyc clan........... well it sounds like its way off balance.

order prop balencer.

Put it on balancer ....
Looks balanced. ok put it back on, same thing. Whats goin on? on the balancer both of the sides do not drop, rather just stay. The only thing i can think if is that the prop shaft hole in the prop was a little tight so i had to sort of "screw" it on. And when i got to the last part of screwing it on The whole shaft would turn so i couldn't put it on any farther. So I think maybe once i start the engince the prop wiggles in the space left that i couldn't tighten it into then it is sort of lose. Could this be it? what do yall think??? Thanks


keep em flyin

The prop needs to be all the way on. The back of the propeller 'grips' to the metal washer that goes behind it. This is sometimes called a 'prop driver' cos thats what it does. It is mainly this bit that spins the prop. The noise your hear may be a little imbalance, but it may be that the engine in turning faster than the prop.

A good investment is a prop reamer. It is a little tool that is designed to open out the hole in the middle of the prop. I think Great Planes makes a stepped one, which will be handy in the future for when you have larger engines.

You could just drill out the hole. Make sure it is no larger than the crankshaft, and as you have already noted, make sure that it is central.

It's noot uncommon to have to "screw" a prop on, but the nut should be able to tighten it all the way down. Once tightened, check to see that the spinner backplate is tight. If it is, the prop is seated correctly.

Make sure that you torque your propeller on tight.
If it moves without turning the engine then it is not on tight.
I would recommend that you use a small wrench and tighten it as tight as you can.

thanks guys i think it is what was said in post 2 by siclick

I'm goin to an advid flyers house toimmorow and bringing my plane so he'll check it otu. So thanks

I noticed that nylon prop on my Avistar is noisy also. Noisy enough that I thought something was vibrating loose. Much inspection revealed nothing loose. Still had noise. Wood props don't make that noise. Don't know, something about harmonics of nylon prop versus wood?

did you check to see if the nylon prop's blade shape is different... allowing the trailing edge of the prop ti hit something that the wood prop cleared?

If the prop ishidding something you get the clickity sound. usually te the throttle pushrod extending through the EZ-Connector... sometimes its hitting a cheek cowl...

VERY slowly rotate the prop with the throttle set tofull (that means the engine is not running) Look for something being hit by the prop.

If anything is within 1/8 inch of the prop... its a potential problem.

Nope, no clearance problems. Props balanced, both nylon and wood, and had noise with three different nylon props. Almost sounds like you have a pushrod tube vibrating against something. But, I checked, everything is tight, clear, and not touching. Prop is not touching spinner, and as a matter of fact it makes noise without a spinner installed. I'll have to see if I can get it to record, and post an mpeg. Really strange stuff.... got a comment one day from someone to the effect that it sounded like the fuel tank was rattling around in the airplane.