Tops Of Pistons - Condition

[benl1981]

Just replaced the spark plugs the other day and thought I'd shine a torch down the spark plug hole.

Now most had a fairly black coating on the piston tops (carbon I would imagine). In some areas you can see the metal.

However, on No. 6 piston there was no carbon at all. You could even see a letter/no. cast in the metal. Is No.6 running leaner or is this normal for it to be different.

Anyone else looked down their holes

None of them had pitting but was wondering if this tells you anything about the fueling and timing.

I pulled out the copper plugs at 35k kms and they all looked ok and consistent.

At one point I connected a vacuum line up to an injctor cleaner bottle and regulated a bit through.

It blew a heap of smoke for a couple of minutes after that ..not so sure I want to do it again..

Edited April 24, 2007 by benl1981

[dontfeelcold]

At one point I connected a vacuum line up to an injctor cleaner bottle and regulated a bit through.

into where?

[benl1981]

Oh yeah.

The intake manifold. I think I connected it where the factory boost gauge taps off..Maybe that explains it then as it is closer to No.6 ??

Edited April 24, 2007 by benl1981

[paulr33]

i think out of the box #1 runs rich and #6 runs lean?

ive seen a few FC's that have less for #1 and more for #6