80 X80 S1100 SG electrical problem in the Philippines

[hanger10]

Howdy all. Well, Im back again. I have posted before about some electrical problems, and you all have pulled me out, but its back again!! I was having a slight miss problem, and lubed the rotating plate on the vacuum advance, and that took care of it for a while. Now, Ive got a miss starting from take off, up through around 3500 to 4000 rpm. Now, if I give it a lot of throttle, it runs fine, but when I just roll it forward, under normal throttle, it misses! No backfires, just misses. My mechanic has read the tech tips from this forum on the coils, and has fully tested them, and says they are within tolerances. He has checked the wiring from the coils back, and they are fine. There is no discontinuity anywhere in that wiring. He has also fully checked all the wiring on the pickup, and that is fine, in fact he replaced them all, but the damn miss is still there! We unhooked the vacuum advance, and drove it like that, and the miss was even worse. He found a vacuum leak, but fixed that, and it still misses. HELP!!!!!!! Any ideas??? Thanks in advance, we are at our wits end!!!!!! I think Ive described the miss pretty well, but if someone thinks it will help, I can take my wife for a ride and video it so you can hear the miss!


Randy
Thoroughly perplexed in the Philippines

PS-He also took apart, and thoroughly cleaned the carbs

[natemoen]

There does tend to be a bit of a stumble in the 2000-3500 ish range frequently, especially if you have something other than stock exhaust. It's usually one of those fine tuning annoyances that seems to take some time to figure out just the right tuning to get rid of it.

A video would help though!

[tinman905]

Hey Randy , can you tell which cylinder you get the miss in . Do you get a blow back through your carb when it misses? I had a similar problem and found it was in my number 4 carb. I went through the carb and it cleared up my problem. I thought it was my coil wire at first .

[Ken Talbot]

Did your mechanic check all four of the pick-up coil wires for "hourglass" problems by pulling vigorously on the wires while the engine was running at idle with the sidecover off?

[bikerphil]

My guess is weak coils, get some 3 ohm for better spark. Did you clip the ends of the spark plug wires? Might be crappy voltage at the red/white coil feed. Just thinkin' out loud.

[TopCatGr58]

Further on what Phil said,

You can do a quick test, and bypass the ballast resistor for s short while, so that the coils get full 12 volts, do a short run to see if it still misses. The 12 volts should provide better power and stronger spark especially at the lower rpms where the ALT isn't putting out much.

THEN, if the miss goes away, you know it's weak coils. IF the miss is still there, then it might point you back to the carbs. But several folks have reported a low rpm miss that was cured with stronger aftermarket 3 ohm coils vs. the OEM 1.5 ohms and Ballast resistor.

T.C.