ORIGINAL: thevirginian

Great idea to start this thread.
I too have a fairly new CRRC 50i Pro. It's a powerful motor that starts easlily and runs great. I have one small issue with it, though. Lately I had the first dead stick coming in for a landing. The motor cut off as soon as I throttled back to idle. When I picked up my plane I found the prop stuck. My first reaction was I have a seized motor. I disassembled the motor right at the field and, to my amazment, found absolutely nothing wrong with the internals. Everything was nice and shiny. As a matter of fact I was very pleased with the workmanship of all the machined parts. Then I found the problem. The crank has a little too much lateral play and can be pushed rearwards about 1/32". Now, this motor does not have a candilever type crank. It is supported by three bearings. That's why she runs exceptionally smooth. When the motor is hot from running, obviously the crank is being pushed back by the braking effect of the slow rotating prop, when the throttle is cut back to idle. Consequently the prop hub hits the crank case and rubs aginst it, which makes it feel like the engine suffered a piston seizure. A slight wack forward on both sides of the backside of the prop frees up everything and the motor turns smoothly again. I tried to pull the hub off the crank, but is is glued on with red Loctide and I sure don't want to heat it up to soften the Loctide. It would, most likely, destroy the magnet that's inbedded in the hub. So I tried to stick a piece of 120 grid Wet -n Dry between the hub and the case and run the motor with a starter motor, with the plug removed. The first flight after this fix was positive. No rubbing. But I still want to prevent the crank from moving axially. Other than this little problem I like this engine a lot.