How does this engine look:
 

have an 0S40 FX that the thread in the glow plug hole is stripped. I ordered a new head and took the old head off of. Looking at the pictures, does the engine look dark to you? Also how do I clean the surface of the cylinder to put the new head on and get a good seal?

Thanks

RE: How does this engine look:
 

Blackening of the top of the piston can mean a variety of things. If you are using a fuel with a lot of castor oil and running rich, then it would be very normal to have some carbon buildup. If you are using an all-synthetic fuel, you might be running a bit lean and a bit hot.

To clean up the top of the cylinder liner, we'd use very fine steel wool. The grade is "0000", also known as "four-ought". It's about the finest grade possible, and will do a very nice job. Use very soapy water or some oil to lubricate the process, and make sure that any filings and steel wool shreds do not wind up inside the engine.

RE: How does this engine look:
 

Thanks for your response. Can I use the steel wool to clean the top of the piston as well?

Thanks