rough idle after running at temp

[mvanalst2003]

I watched the video of your bike idling. I recently bought a 92' with 9700 miles on it and it is doing this exact same thing. I'm trying to diagnose it as well. I'll check the battery voltage tonight. Although, I suspected the carbs being a little dirty, so I ran a 1/3 bottle of Seafoam and it idled much better for that tank. As soon as I filled it back up with gas, it would get warmed up and idle awful like this again.

Has there been ANY resolution to this issue? It's been over a year since the most recent post.

I appreciate the help.

 

[jfeagins]

Welcome to the form mvanalst2003.

When mine did this, you could see spark jumping from a plug wire and onto a valve cover as the motor missed out and would want to die. More easily seen after dark. Low voltage as my fan kicked on was the culprit. I have absolutely no idea why low voltage to my CDI box would cause spark to want to jump from perfectly good new plug wires, good new plug caps, and good new sparkplugs, but it would. I upgraded to the newer style r/r for better idle voltage and also did the bigger battery box mod, for a larger battery reserve, and it fixed my problem.

 

[motox909]

this was exactly how my bike was running. I tried everything and then changed the caps on the plugs. bought the ngk straight caps and an accel wire from the auto parts store. cut the wire to length and used some dielectric grease. the bike runs great now even when the temp is in the hot range.

I found out the problem by touching the caps and the rubber while it was running.....I WAS GETTING SHOCKED SO DON'T DO IT IF YOUR NOT WILLING TO BE HIT WITH THE VOLTAGE!!!