Electical issues

[zr2highrider]

So if finally got another banshee. Its a 89 j arm with some work done to it. I was playing around on it yesterday and once I got done riding, I was going to play with the idle - it acts like your giving it gas at times and revs up and at other times, it goes right back down to an idle. Thats besides the point. I shut it off, and then tried to start it again. I noticed the idle was once again off but one of my pipes was completely cool while the other one was warm. (the bike had plenty of time to cool down - so it was like a cold start). I checked and changed the plug that wasnt firing and still had the same issue and acted like it was running on one cylinder. I killed it once more and tried to start it again and I got no fire at all. So I got on here looking for awnsers, went back to ohm out the stator ect, ect, and remeber seeing a post on the "smack test" on the cdi. I tried it and the shee fired right up. Any ideas of whats going on? Is the "smack test" complete bs? Could my speratic idle be ignition problems? Or could it be my stator or coil? Thanks.

 

 

[Jereme6655]

your speradic idle sounds more like an air leak issue to me. as in your leaning one side out so much that its reving on its own (natural side effect of air leaks) and its not starting cause its not getting the right air fuel ratio. i'd build a leakdown tester and check your engine before you lean it out so far that it grenades your bike....

[ginger]

i agree sounds like a air leak, leaning out one side. could be anything from a cracked intake, to blown base gasket.

[blowit]

Hard to say where your problem lies just yet but if you have electrical issues, you need to sort that out first. The CDI usually fails due to failure of internal capacitors that fail to retain energy for a spark event so the spark energy gets less and less as well as produce sporadic spark. HOWEVER, if you are firing on one cylinder, the CDI is NOT the issue. The CDI creates spark energy twice per crank revolution with only two wires to the coil. In short, the ignition coil acts as a spark splitter. There is no way for the CDI to fire only one cylinder. I highly recommend you remove the ignition coil and bench test it, as well as the wires and caps separately. the caps and wires are very known for failure in which most people will misdiagnose this as a bad coil and replace it.

 

Once you know things are firing right you can move on. I also think you might be fighting a carb balance or sync issue in which one side gets more fuel/air than the other at idle. This will be proven by swapping the spark plug wires. if the weak cylinder stays on the same side it was, you are likely fighting carb issues, not ignition issues.

 

Brandon

Mull Engineering

[zr2highrider]

Ok i think that i have narrowed down the ignition problem-bad plug wire. I could wiggle the right plug wire and it would stop running on that cylinder. As for my air leak.... Its not all the time. Thats the thing thats getting me. It will idle fine one minute, give it some gas, goes back down just a little above idle, give it another brap, and it falls back to an idle. I sprayed gas around the intakes and didnt change idle. Ideas? Dirty carbs? Not synced?

[blowit]

I am not convinced that you have an air leak. More like carb tuning, cable issues, lean pilot jetting, or poor carb balance.

[zr2highrider]

Im back to an electrical issue now. I was riding yesterday and it started cutting out on the left cylinder. Took it home, and started to test everything. Stator checked out good at 15.6ohms, pickup was at 126. Took the coil off the bench test it. Tested it negative to positive on the terminal ends and I got nothing. Negative to plug boot; only 1700. So im 99% sure my coil is bad. My last shee did this to me also and i bought a new coil but it turned out to be the cdi as well. Does one tend to go and then the other? I plan on heading up to F.A.S.T. next weekend to pick up a coil, should I pick up a cdi as well?