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Scott Wolthuis Scott Wolthuis is offline
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Join Date: Nov 2001
Location: Weatherford Tx. USA
Posts: 98
If you're talking about the clean part of the piston (upper right hand corner) I think it's caused by incomplete combustion/unburnt fuel.
I think Smokey Unich's books talk about this and how to remedy it.

Scott
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Old 01-04-2006, 09:54 AM
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