What can you check on an engine when you have very little compression when you turn the prop over with the glow plug installed?

Thanks,

The only compression that matters is when in the motor is hot.

Does the motor run well?

compression at room temperature really doesn't tell you a whole lot.

Is the cylinder dry? Prime the motor with a little fuel and see if the compression picks up. Dave is correct though, the only compression that matters is at running temperature.

Thanks guys. I put in a new piston and sleve. That did the job. Now it is running around 16,500.

Mike

sometimes cleaning the varnish (oil residue) off the piston will increase RPMS. This is different than compression, but often many feel the engine is shot when it will no longer turn up or keep up, when all it needs is a good leaning of the piston.