Big Dave

What's the best way to clean off the top of my pistons? There's some black soot on them, and I'm not taking the bottom end of the engine apart, so they'll need to be cleaned while still inside the cylinder.

I don't need them to look new. I just want to get some of the heavier stuff that isn't flaking off. Would mineral spirits hurt the cylinder or rings?

Should I just use a rag and wipe them off and not worry about any soot?

BC

Simple Green has worked great in the last few days for me, but thats outside the engine. I'm not sure about when assembled. I'm very concerned about the soot that would clearly drop down to the sides and get into the ring area.

Big Dave

I'm going to vacuum out the loose stuff so that it doesn't drop down into the coolant passages. Then I'll flush out the coolant passages with distilled water to get rid of anything else. I guess I'm just asking what I can use to clean up the piston heads without risking harm to the pistons, the rings or the cylinder walls.

Kevin in Atlanta

Get a can of carb cleaner hose it down and let it soak over night. Use a brass detailing brush and brush it off. You can rotate the motor on the stand to empty each piston.

Jeff McVicar

Ditto dave.............just blow them out with forced air when you reassemble