I was flying my Spectre the other day OS 91 VR DF when the engine went lean in the air and quit. I normally run the aircraft rich so I tracked down the problem. It appears some dirt
had choked up the fuel filter. I guess it got in through the pitot tube of the fan as I fly of grass.
The engine now lacks compression. Is this one short lean run enough to damage the piston /liner ? I have tried to take the head off but can't loosen all the bolts. Now I have one of the bolts with a rounded head from the allen key . HELP ! How can I get this and the other bolts loose?
If I need to change the piston liner should I change the bearings as well? The engine has done about 40 flights. What would normal wear be for pistons and bearings?

Thanks

Hawkflyer.