Help..One nasty plug

[roadrash]

Hello all,

When I checked my plugs I noticed that one is much blacker than the rest? (considerable difference) What could be causing this and what should I do? thanks guys!!

[duff daddy]

ah, it could be a lot of things, too much fuel getting in to that cylnder so its fludding causing carbon build up, ah the plug may have just been bad so it was a weak spark wich still fired but not good enough so it wouldnt burn it all, just get a new set of plugs and check them see how they are burning, could also be a bad wire or the terminal on the wire at the coil could have had some debreis on it

[The CyberPoet]

Start by replacing that plug. Then clean your carbs using an in-tank fuel system cleaner (Techron is my recommendation -- 1/3rd of the bottle to a full tank of gas), and finally get your carbs sync'd.

Basically, that one cylinder isn't pulling air as well as the others, or is putting out more fuel than the rest; my guess is air. The reasons for this can include:
Valves out of adjustment compared to the others;
Carbon or sulfated ash build-up on the valve face;
Carbs not sync'd properly;
Rings damaged (usually in conjunction with a previous carb fueling issue related to fuel leaking into the cylinder when parked);
or vacuum leak (usually at the vacuum nipple for the carb where the sync tool connects, if there were no other symptoms).

Cheers
=-= The CyberPoet

[md86]

Or something is stuck in the float .