plug fouling

the #2 cylinder plug keeps fouling on my '78 KZ650. the other ones haven't had any problem. So I'm wondering if maybe the #2 cylinder is running too rand and the carbs need to be synced or if the #2 carb needs just an air/fuel adjustment. The ignition is the old points system. I am going to try to install the Dyna s system this winter maybe to try and get a stronger spark.

rkan wrote:

the #2 cylinder plug keeps fouling on my '78 KZ650. the other ones haven't had any problem. So I'm wondering if maybe the #2 cylinder is running too rand and the carbs need to be synced or if the #2 carb needs just an air/fuel adjustment. The ignition is the old points system. I am going to try to install the Dyna s system this winter maybe to try and get a stronger spark.

If not already done, would do the following:

Check #2 compression and valve clearances.

Remove #2 plug and visually inspect spark quality. Look for fat blue spark.

Use clear tube test to assure correct fuel level in #2 float bowl. It might be too high.

If pods are fitted, assure #2 pod is clean, not over-oiled, and breathing clearly.

Install brand new sparkplug and test run.

If #2 fouling persists ---

With side-located pilot air screw, turn out counterclockwise 1/2 turn to lean pilot circuit mixture.

With bottom-located pilot mixture screw, turn in clockwise 1/2 turn to lean pilot circuit mixture.

Could try some Seafoam added to fuel tank. Is a long shot effort toward clearing internal carb pilot circuit.

If #2 fouling persists, the carb likely needs disassembly and cleaning, especially all pilot circuit air and fuel passages and pilot jet.

Good Luck!

What plugs are you using? Ed

could also be a bad plug lead try switching 2 and 3around and see if the problem changes cylinders

ngk b7es