Frank RKS

My engine has been sitting on a bench for a couple of years so naturally it was a bit gummed up. I managed to free up everything to the point that it would turn over easily by hand - just turning the shaft with the plug out. However, when I put a prop on and tighten it up, I can't turn it at all. It looks like the prop driver (drive hub) is binding on the front of the engine. I did crash this engine nose first which is why it's been on the bench.

So, I'm wondering what damage I may have caused and what I can do to remedy this problem. Any good advice appreciated.

2W0EPI

Remove the glow plug with the prop on, see if it turns over easily or not.

If it free up with the glow plug out then you have fluid in the engine,

If it is still seized with the glow plug out it looks like you have frontal damage from the crash.

Frank RKS

Your third point is the most valid. Plug out, no fluid in the engine, and it turns easily. Put the prop on and tighten and it won't turn at all. So probably some sort of frontal damage from the crash.

Question is how to fix it. A small shim between the engine and prop driver ???? New bearings ????

A. J. Clark

Take it apart to make sure the crank is seated all the way in the bearings. Just tightening the prop might not have enough force to pull the crankshaft out if it's not all the way through the bearings. Might have rusted setting all those years.

Jesse Open

Also make certain the rear ball bearing outer race ring is fully seated, bottomed out in it's bore.

kakariki

My Feedback: (6)

Is the black thrust washer installed behind the prop driver and in front of the bearing, this is a common fault when the prop driver is removed that this thrust washer falls off and is not noticed.

qazimoto

My Feedback: (1)

It's a common problem. Take the backplate off and insert a phillips screwdriver or similar into the hole down the crankshaft. You may need to turn the crank so that the conrod is out of the way. Hold the engine and screwdriver in your hands and get someone to gently hit the handle with a hammer. A short sharp shock is what's needed. This should force the crank back into position forward in the case. Don't hit the screwdriver too hard and it shouldn't do any harm..

jaka54

I would take the engine apart! -So easy and takes only a couple of minutes.