Hey guys, Any help is appreciated. I have a scrambler 500. I noticed the starter was arching fire and it would misfire once in a while. I thought the starter was shorted and replaced it. It didn't arch anymore but when I started it the headlights got real bright and blew and the scrambler was missing even more but it was running. It would run good for awhile then miss for a while.
Now it's gotten to where it won't run at all. Just backfires as I try to start it. I've taken the flywheel off and its not out of time. It is dirty in there though like maybe its been wet at sometime or another.
I guess my question is, does anyone have an idea what the cause of my problem may be? Also Is there a way to test the stator,cdi box, or coil with an ohm meter or something to see if they are bad. That would be really helpful. The parts are so expensive you just can't start guessing or it could break the bank.
Oh yeah, I also noticed that one of the connectors looks a little burnt on one of the yellow wires on the little box that is mounted on top of the radiator. I'm not sure what that box is.

 

I started it the headlights got real bright and blew and the scrambler was missing even more but it was running.
Oh yeah, I also noticed that one of the connectors looks a little burnt on one of the yellow wires on the little box that is mounted on top of the radiator


Bright lights and blew out when increasing the RPM of the engine?
Carefull you do not blow the battery up.

Rectifier/regulator. OVC (over voltage condition)
See if the yellow wires goes to the stator?

If so you may have done more damage to the electrical system, when continuing to run the machine.

 

Yes the yellow wire does go to the stator. I found it while checking all connections and putting dielectric grease on all of them. The connector on it was just a little discolored to a brown color not actually burnt. I didn't increase the rpm. It did it on start up at an idle. It ran ok but started to backfire a little while riding after that. I put a new light on and it works fine using the stock wires. The backfiring got worse over a few hours of running it and now won't start.

 

See if the battery charging system is working.
From what you described about the yellow wire to a box on the Radiator. I think it may be the rectifier/regulator.
If the charging system is not performing as required, the battery may be strong at the start and then when riding it may be dropping in charge.
If the rectifier/regulator is not working the voltage from the stator will not be filtered it will pass the voltage but it will not be a straight flat DC voltage. Get a volt meter and see if the charging system is at fault.
should be checked at the batery terminals and shuld have a value larger then 12 volts
12.5 -14 v

 

At the stator....

wh/rd to wh = 185ohms
wh/rd to ground = open
y to y = .43 ohms
y to ground = open


at the ignition coil....
primary = .11 ohms
secondary = 6.7 ohms

above measurments are plus or minus 10 percent


at the battery....
better than 13 volts at 3000 RPM

If all measurments check out than check switches and wire condition. If switches and wires check out than its the CDI.

I suspect you'll find a fault (likely to ground) on the yellow wires.

 

Ok I have checked the ohms on everything. I have one plug with red,green,and black/red wires coming from the stator(other plugs check out). Red to green shows resistance. Black/red in conjunction with any other wire shows no resistance at all. From everything I can see this is wrong. Does this mean the stator is completely bad or do the coil bobbins just need to be replaced.