dry fouling plugs???

[79ATC110]

can any one tell me if dry fouling plugs is related to a too lean condition? I've been messing with the carb. tune, but no matter what I do I cant seem to get it to run good in the mid rpm range...any ideas?

[jeswinehart]

Dry, fluffy carbon fouling is normally related to spark-ignition trouble.
Anything from weak spark to timing being off a wee bit.

john

[TeamGeek6]

No, thats not too lean, its too rich or weak spark. "Dry" is carbon deposits from excess fuel and should indicate the engine is normal temperature or even too hot. "Excess fuel" could be carb problems or ignition. That you cant seem to get it jetted might indicate fuel level problems, bad float or needle.

Smell the exhaust, thatll tell you whether its fuel or oil. Restart with a new spark plug or you cant tell whether its fuel / oil causing it, or a bad spark plug.

Honda motorcycles are plagued with wiring problems so dont be surprised if the ignition is falling on its face. Had to totally rewire my 250R.

Stuff a piece of wire in the spark plug cap and tape it around the spark plug ceramic so the bare wire end is about 1/4" from the spark plug terminal. Start the engine, should get a blue to white arc in the dark. If its yellow or orange, its probably weak ignition. Very common problem in old cycles. If its weak, disconnect all the plugs in the wiring harness and reconnect them half a dozen times and try again.