Carbon in head of engine

[Andrew]

After removing head of engine I discovered a lot of carbon inside of head. On pistons, valves, manifold, whole exhaust systems.
But cylinders and plugs seems to in good condition.
Please advice what is wrong.

P.S. I tried to find answer in past discussions, but I didnt find the equal subject.

[m3a1]

My first thought is, incomplete combustion is probably the reason. Anything that might cause incomplete combustion is a possible root cause, including, but not limited to - incorrect spark plugs for the application, poor fuel quality, maybe even poor compression).

Don't know if anyone has ever studied what might happen if an engine is run only very briefly again and again but, I suspect engines not run long enough to be brought up to temperature under such circumstances might cause a lot of carbon build up.

The first three things I've mentioned are very easy to check.

Cheers,
TJ

[rickf]

Running with choke on too long? Dirty air filter? Running too rich from high float level or high fuel pressure? Or, as TJ said, start/stop many times with no chance to warm up and no load. You are really not giving us much information or backstory to work off of here. Why did you pull the head off to begin with?