DAVE SHADEL

I have a YS 120 FZ that I haven't run for 2 years, in a Dave Patrick Ultimate Bipe. Last week I wanted to fly it. I rotated the prop with my finger and felt practically no compression. I assumed a valve or valve seat was the problem. I gapped the rockers arms, no change. I pulled the head off and the head looked clean and so did the valve seats, although I don't know how to remove the valve springs. I put it back together with a new glow plug, and thought what the heck, I'll fly it anyhow. When I started it and then stopped it, I felt some compression. I took off and made my turn and didn't like the pulling power of the engine, I was using a 16-8 APC. I did a couple of rolls and the plane was boring. I changed props to a 15-6, got 10,420 RPMs. Still no better in the air, but it seemed to pull well on the ground. I'm using Cool Power 15%
Actually, I'm not sure it ever ran as expected as I was bored with the plane and hung it up after
two flights. I have had YS engines in the past, but they were .60 and .61 engines for my pattern planes. Not feeling any compression really stumps me.
If you can't offer a solution from my description, tell me who to send the engine to for checkout and repair.

Regards, FRED