Perhaps the coils?

[audijunky]

Is there anyway or has anyone had a problem with lower rpm performance( lets say idle to 3K) and the ignition coils been the problem? How about the alternator(or whatever it is called) the thing with the windings on the right side of the motor?

[John]

Usually, any problems in the idle-3000 rpm is the pilot circuit in the carbs. If it were coils, they'd be bad at a higher rpm Iwould think.

[planedick]

Actually yes...

I spent weeks chasing carb problems with that kind of reaction. Really crappy running under 3 grand, wouldn't take excelleration, but when I got past 3500 it run pretty good up 'till around 6000 then crappy again. I learned lots about removing and installing carbs, but the real lesson came when I tried different coils. When you got good spark, it will run darn good at most any setting. Seeing a spark with the plug outside isn't enough. A weak spark will not work when under compression with wet gas on it.

[audijunky]

Thanks guys, I have been screwing around with the carbs since I purchased the machine, Since I bought it and got it running it has hestated until 3k, than it is off like a rocket till redline.(around 10K I guess). I have done everything to idle circuit you can think of, even got the idle screw stuck and had to drill them out (carbs 1&2) Now in the process of putting 1 non-drilled out carb in position 1 and 1 not as bad as the one I had but still drilled out carb in position 2. Carbs 3+4 run awesome, good color on plugs nice smooth idle. Carbs 1+2 rough idle and dark plugs. I turned the idle screws in on both of them all the way to close it and the idle didnt change at all. So I figured the gas was still getting to the motor.( bad job drillin out the broken screws?) When I had it runnin I could feel the difference in the exhaust pipes 3+4 exhaust had a nice rythm at idle and no smoke. 1+2 had a sporatic rythm or no rythm at all and smoked a little. So hopefully putting in these other carbs will make difference( better)
Thanks
Steve

[mason79]

same crap on my bike, and now coils are inroute, the old teenage swap a new part type diagnosis, hope itr works

plandick you said your ran bad over 6k my goes good to redline, go figure...

[audijunky]

mine also goes good to redline, So we may have a different problem than planedick..... I hope my coils aren't bad

[audijunky]

Is it possible to switch coils for diagnostic purposes? I am sure you would have to switch input wires as well as the spark plug wires. You should beable to do that right?

[mason79]

plandick was going to swap out his known good to my suspected bad, but i didn't want to ride the 35 miles with the bike running so sh*tty

[audijunky]

What I was trying to say was switching the coil for 3+4 with the coil for 1+2, since I know that 3+4 carbs and coil is good. Just trying to isolate the problem.

[randy]

audijunky,

the coils are wired 1/4 and 2/3. I'd venture to say that if 3/4 have good spark, then 1/2 probably have good spark. Are your 1/2 plugs clean? Sometimes troubleshooting carb problems can cause you to foul the plugs, further frustrating you. Make sure the plugs are clean before you proceed.