Majortom,

This is one instance when you need to exercise your warranty.
Just take your engine to the LHS, or whoever sold it to you and get a replacement free of charge.

I have seen all kinds of machining junk inside an engine, which will make your engine very old, before the break-in is even through.

Just so you don't trash the replacement as well, remove the head and the backplate, just before mounting your engine on the test stand for break-in. Wash it out with methanol and verify no particle, aluminium, steel, brass, or chrome is in the engine.

Oil and reassemble the engine properly and perform the break-in in accordance with this thread:

http://www.rcuniverse.com/showthread...59&forumid=145

Sincerely,,