I am running a 914. I was concerned when I found the amount of accumulation on the plug (filings ok, chunks not) and also metal separated from the filter material at roughly 100hrs. I was assured that when the engine is fully broken in, it would stop, and it has. Last oil change had a completely clean plug. However, it was believed that setting the idle too low is what may have caused increase gearbox wear since the previous owner had the idle set to 1,450rpm. 1,750rpm and the engine past the 100hr mark has yielded no further issues.
As long as you have followed prior recommendations, this should pass. As per info from Lockwood.
