iflircaircraft

Hi:
This is my third season running an OS 1.08 on my Super Skybolt. Up until a couple days ago I haven't even had to change a needle valve setting or a glow plug.
As I was flying Tuesday the engine quit, so I had to try to land it dead stick. Well, I didn't quite make it back to the field and "landed" in a sticker bush, which in hindsight was better than the plowed pasture I could have landed in.
There was no more than a couple of holes in the covering, so I felt the rest of the plane would be ok.
When i got back to the pits i rotated the prop and it was sticking at TDC.
I took it home and inspected the glow plug.
The entire coil was missing from the plug.
I took the engine from the plane and removed the cylinder head and found silver particles on the piston and inside of cylinder head.
I cleaned them up and found some minor pitting on the piston and cylinder head.
It didn't seem to be serious so I put it back together and installed a new OS #8glow plug, put it back in the plane, cowl and all.
The engine won't run on less than half throttle no matter where the needle is set.
This really has me stumped as I never had any problems in the past with this engine.
Any ideas?

Tom

w8ye

My Feedback: (16)

Would those silver particles be part of the rear bearing cage that's gone on top of the piston and blew out your plug?

Enjoy,

Jim

iflircaircraft

Jim:
You mean I'm NOT supposed to see the balls in the bearing?
I guess I'll be ordering new bearings!

Tom

w8ye

My Feedback: (16)

The cage holds the balls evenly spaced within the bearing. When it goes, the bearings will bunch up in one place and another and cause a lot of vibration and low performance.

This was most probably caused by corrosion (rust) on the bearing.

Enjoy,

Jim

iflircaircraft

Thanks Jim