checking some things on my engine and I pop the head today and i saw that typical carbon build up on my pistons how can i clea that up without scratching my pistons .. I try to use something sharp but it scratch them .. anyone have any clue ?

 

Scotchbrite should work fine. Or you could run some of that Engine top end cleaner through it. It works pretty good also...

 

other than carb cleaner, i'd use steel wool or some fine sand paper. Scuffing the piston helps remove "hot spots" which could cause detonation