Intermitent Weak Spark

[KenC]

Last trip to the dunes on the last day my 96 Banshee started to run a little rough in one cylinder. I sprayed some lube around the reed cages and the idle changed. After trying to make a quick fix The bike would no longer start without starting fluid so I thought that maybe some top end damage had been done. I took apart the top end and had my machinist spec everything. He said the rings were a little worn but everything was in good overall shape. He honed the cylinders and I put in some new pistons/rings. The bike still wouldn't start without starting fluid and runs poorly. I cleaned the carbs and checked the spark. It is there but very weak. I took apart all wiring connections, cleaned the run/off switch and basically made sure everything wiring was clean and connected. At one point I was checking the spark with the plug in the boot and it was great, then it went back to weak. I thought maybe it was my coil or CDI so I borrowed my friends coil/CDI from a running bike. The spark is still weak and the bike won't start. At one poing again while checking for spark it looked great then back to weak.

I am at a loss. I have a feeling that it is the stator or something under the side cover at the end of my crank but I don't know how to test for that. Everything under the stator side cover looks clean/dry and nothing appears loose.

Any suggestions or advice would be appreciated. I am hesitant to take it to a shop for an electrical problem but it may come to that.

BTW, the bike is mostly stock with pipes and a filter.

[BenBB]

Nooo not the shop!! :yucky:

 

Testing the stator is easy, you just need an ohmmeter (specs in Clymer manual or Electrical FAQ below). You already ruled out the CDI, that's a good thing, usually the hardest one to test if ya don't have access to another CDI. Anyway the stator is a good possibility, they are known to fail eventually, definitely check that first. It could also be coil or wiring, if your buddy will let you, try swapping the coil with his (or have a shop bench test it, I've never had any luck testing a coil with an ohmmeter). It could also be a loose or bad ground, make sure the black wire on the harness is crimped well to the eyelet terminal and the terminal makes good contact with (preferably) bare metal on the frame, back under the seat where the voltage regulator bolts up. If all that checks out you'll prolly need to check the harness for continuity. Good luck, electrical problems can be a pain to find but you can do it if you give it a shot...

[KenC]

Hey Ben, Thanks for the reply. I did use my friends coil and CDI, I also ran an additional ground to the frame right off the coil. I am probably going to go buy a Ricky Stator and install it. I am fairly certain that is the problem. Its funny, I own 5 2-stroke street bikes, a CR250 and 4 quads and this is the first time I was actually thinking of taking something to a shop

[travis6767]

before you go spend the money on a stator check the pic up coil gap, it should be close to .020"

[KenC]

I replaced the stator and still have the same problem. I have checked all the wires for continuity and they all check good. I bought an ohm meter but I am at a dead end as to what I should check next? This really sucks

[Onesickcrewcab]

Have you checked your pickup coil gap? Sounds like the only thing that could be left. Is your harness in good shape? Not burnt against a pipe or anything?

[KenC]

I adjusted the pick up and unwound the wire harness and all the wires look to be in good condition. I have given up at this point. I will hopefully find a good mechanic to get it fixed.

[sinisterboo]

If all this didnt fix it, Id say try a new set of plug caps. I see alot of guys blame the coil, but we have seen maybe 2 bikes with bad coils since 87! Not saying they dont go bad, just saying its rare. Try the plug caps first, and you said you tried another cdi box? thats most common prob. And good luck with that ricky stator.