[11echo]

I'm guessing your engine is on a stand? Rotate the engine so the it's oil pan is up, then get a putty scraper and go for the tops of those pistons. Just be careful that you knocking off the carbon and not gouging the top of the pistons. I have used a wire brush on a die grinder as final clean up. So your NOT trying to really get after it, just a "light" clean up. With the engine in this position you shouldn't have to worry about "cr*p" getting into the engine or space between the piston and cly. wall. IF you do all this then rotate the engine back up-right and squirt some heavy oil onto the cly. walls and rotate the crank, if any grit got between the walls it will show up in the oil as you rotate the crank, just wipe it clean. My 2 cent anyway, Good Luck! ...Mark