hey guys, whats the best stuff to use to clean the tops of pistons and walls?
the pistons are black and on the top of the walls were the ring land meets is all black and gummy.
thanks
-Steven

Carb cleaner is good for cleaning coke & carbon.

Ditto on the carb cleaner. I tried all the other remedies and it works best by far.

Assuming you're not planning on removing the pistons, I like to scrape off as much of the buildup as possible, with a shopvac hose in the other hand to immediately pick up the debris and keep it out of the top ring land.
A straight edge razor blade will remove the buildup from the top of the cylinder, same drill with the vac.

I use a phenolic scraper that I fabricate from sheet stock on the belt sander, made to the shape I need. I use a shop vac like Jim suggests, I also use an air powered vacum with a very small hose fitted to the end to get into tight areas, Snap-on makes these. Then use Dupont Sontara lint free disposable rags and MEK. MEK is highly flammable, but since it evaporates so quickly there is no fear of any remaining in the engine or finding it's way into the oil. Change your gloves every 3-4 minutes as it will leach through after a while and use MEK only in well ventilated areas. There are health concerns with MEK so I don't suggest using it without understanding the MSDS sheets.

Carb cleaner: There's two types. The environmentally friendly stuff and the nasty stuff. Be sure to get the NASTY stuff. Oh, keep it AWAY from paint that you don't want to replace. Kinda like brake fluid.

Brakeleen and scotch brite followed by a good blast of compressed air.

thanks guys!! i also want to take a pic of the tops of the walls where there is no gunk. they seem to have little burn marks up there. i want to get your guys opinions if its ok or if the gaskets werent sealing good there
-Steven