What can cause major carbon on the heads after 5,000 miles?

Joe Boone · Post by **Joe Boone** » Tue May 25, 2004 10:18 am

What can cause major carbon on the heads after 5,000 miles?

I had to do a tear down for other reasons and found a thick buildup on my heads and on the top of the pistons.

Is this carb jetting? (Has 40 IDF's on a 1775)

prerunner1499 · Post by **prerunner1499** » Tue May 25, 2004 10:36 am

A little carbon build up is normal,, but if its like 1/6-1/8" thick you got some issues my friend. Might try setting timing a little more like 28-30 degrees at full advance on the dizzy, then going a tad leaner on the mains or higher in the air jets.
What are the spark plugs looking like, are they all gooked up too? They should be a little black/brownish and not all carboned up.
Might even try a little hotter plug to get a better burn.
If its not jetting maybe your rings did not get seated well in the break in and you have some blowby?

Guest · Post by **Guest** » Tue May 25, 2004 11:40 am

It apears to me that the rings didn't seat. The piston skirts are also pretty black.