Trouble Shooting an Ignition Problem

[Guest]

Hey guys I need a little advice on figuring out the ignition problem. I have a 1982 gs650gl and under 1/2 to wot I have a bad stumble right around 5500 rpm almost like it misses like hitting a rev limiter and it doesn't want to go to red line it will but it struggles and sounds like its breaking up. Anything under 5500 rpm runs like a top good power ect. Also at cruising speeds like 55 mph in 5th gear rpm will fluctuate 500 rpm constantly up down up down you cant here it but I can see it on the tac.. I have a volt meter and know how to use it but I have no idea what to test for. I have read the ignightor is bad at going out on these bikes.

Any help would be great
Thanks,
Taylor

[posplayr]

I have seen low voltage to the coils act that way. With key/kill switch on what is the voltage from from battery (+) to coil (+)? If too much it can give problems due to dirty connects causing low voltage and weak spark.

Also just check the Coil (+) relative to ground. I have seen 10.5V cause problems starting.

Get contact cleanser, clean fuse box, and ignition switch and connectors to ignition /kill switches. Or do ignition relay mod.

[brveagle]

Sounds more like a jetting issue than an electrical gremlin.

[posplayr]

Sounds more like a jetting issue than an electrical gremlin.

I assume you mean carburetion (e.g. clogged carbs/jets); No mention of any mods so why would jetting suddenly be off?

[tom203]

"....Also at cruising speeds like 55 mph in 5th gear rpm will fluctuate 500 rpm constantly up down up down you cant here it but I can see "

You sure rpm is really changing this much? This would be an unpleasant sensation! Maybe the tach/drive cable is screwed up.
Have you done the Quick Test stuff to rule out any odd charging issues as rpms go up?