1979 GS750 Spark plug cap question

[Guest]

Hey guys, I got a 1979 750 in various state of repairs. I read through the forum yesterday about the spark plug wire resistances and coil resistances. Coils check out good but I had one spark plug cap read 8.8Kohm. The rating on the side was 5 kohm and all they others read 4.8-5 kohm. Just wondering if that would cause a random misfire and poor idle on that one cylinder. I ordered a new one just to be sure, but Im just curious.

Thanks guys.

[tkent02]

Yes, it's usually corrosion in the connections to the resistor inside the cap. Look in where it snaps on the spark plug, the connector there has a slot for a screwdriver. Unscrew that, take it all apart, clean it up. If the resistor has failed replace it with a solid piece of metal like a bit of welding rod or thick wire. Trim a 1/4 inch of the spark plug wire off, and screw it back into the cap, since the ends of the wires tend to corrode too.

[andy10889]

Got it, Ill have a look. Either way a new one is on the way. Thanks for the response.