major valve carbon deposits, low compression

[mauijim7777@hotmail.com]

had low compression on #1 #2 cylinder. pulled manifold, valve cover, and checked valve clearance. all valves seamed to be moving freely and clearances were ok. did notice a big chunk of carbon in the fuel valve intake port for1 and 2 cylinders. decided to pull the head and check cylinder wall.
all cylinder walls look good, but when i was checking to see if valves were closing, noticed major build up on the valve face and valve stem and valve seat. could this be causing low compression. and how do i safely clean.

[hanleyclifford]

Since you have the head and manifold off you can safely clean with any number of scraping, poking and brushing tools in one hand and a running shop vac in the other, rather the way a dentist works on one of us. The root cause of the buildup is much more difficult to figure out.

[Qben]

What does the buildup look like. That may give some clues to the source. If it is sticky "carmelized goo" it points to elevated exhaust backpressure. I have some good pictures I can post of what this looks like tomorrow.

Qben Oliver

[Qben]

Pictures as promised over at the other thread. Post #9.
http://www.moyermarine.com/forums/showthread.php?p=20734#post20734

Qben Oliver