Carbon build up
HI again, yet another question
I was checking my air filter the other day and had a look down the inlet of the top cylinder while I was there.
I noticed that there is a large amount of what appears to be carbon build up on top of the inlet valves, the entire surface that doesn't touch something is covered and it looks quite thick.
What causes this and is there anything I can do about it without pulling the engine apart, eg spray on cleaner to loosen etc? I was recommended an ether based spray on carb cleaner but this atomises before it lands on the valve heads so doesn't seem to do anything.
As usual all advice welcome.