| You've got good advice on the gage nut.
Actually, the carbon buildup should be self limiting if the engine is
not burning oil. A relatively thin layer of carbon on the pistons &
chambers  is actually beneficial. It helps prevent combustion chamber
heat losses & improves efficiency.
Racers pay big bucks to have the piston tops & combustion chambers
ceramic coated for the same purpose.
Dave Russell
BN2
KingR44916@aol.com wrote:
 > in the process of doing the head is there a way of getting the nut
 > that holds the temp gauge off without cutting it .also there is a lot
 > of black  carbon i guess on the top of the pistons is that bad and
 > how do i get it  off
 |