This is a Warrior Question for a buddy of mine. His starter quit, seems to be an opened ground circuit, He has been told that the CDI has gone out and need to be replaced. Has anyone heard of a CDI keeping the a started from working? I know it's a Yamaha, but the Bomb guys just seem to know more., I guess that's why they ride the real thing[img]i/expressions/face-icon-small-smile.gif[/img].

Any Ideas?

If you jump the Ground it will turn over but won't start.

 

have you pulled the plug to see if you are getting spark when you jump the ground? i figure you are not. don't i recall your a sparky for a job[img]i/expressions/face-icon-small-smile.gif[/img] there should be a wiring sismo you could see at the dealer if there a cool dealer and that would show if there is any starter connection to the cdi.

 

I'm not terribly familiar with the electrical on the warrior ( although I used to own one) but here is kinda the sequence of the average starting system and maybe you can identify the parts on the warrior and get a wiring diagram and do the trouble shooting.
let's review:
1. make sure that the battery is in excellent conditon - DO NOT SKIP THIS STEP , test it under load and make sure you have 10-11 volts under a cranking load. A weak battery can make other components appear to be malfuntioning- jump it if necessary as long as it a 12v
2. The batttery sends power to the starter via the starter solenoid after the start button is depressed.
3. As the starter turns the motor over, the raised tab on the flywheel sends a signal via the triggger coil ( magnetic field is broken and creates a small voltage signal)
4. The small voltage signal goes to your CDI and that in turn sends power to your ignition coil and that sends amplified voltage to your spark plugs and provides spark to the combustion chamber.
5. IF a regulated supply of fuel is present and the spark is well timed then combustion will occur and the engine will cycle and produce power.

now to get to your question

If the starter is not turning over when you push the start button than you have either a bad starter or bad power supply to the starter or a bad ground maybe even bad starter switch, since you can get the starter to turn over when you jump the ground ??? not sure what you mean cuz most are grounded to the engine itself, maybe you're jumping the power from the battery directly to the starter??Either way you need to determine with a volt meter where you are losing power to the stater motor or if you are receiving voltage? GET THE STARTER WORKING PROPERLY FIRST!

But regardless you had it turn the motor over and it still wouldn't start so you need to determine if you where gettting
a signal from the trigger coil to your CDI and then to your spark plugs.
The starter should not adversly affect the CDI but if it's not turning the motor over than you're not generating a trigger signal so the CDI doesn't know the motor is turning over. The voltage rectifier/regulator however could very well be causing CDI issues , in fact defective regulators can damage a CDI by letting voltage spikes thru and taking out sensitive components in the CDI box.

It sounds like you have mutiple issues your dealing with, just start with one component at a time, see if the manual has static and dynamic test for the various components and start going thru them one at a time.
If there is an rogue (unregulated) electrical supply on the bike and your buddy puts a new CDI on the chances are pretty good that
he'll wipe that one out as well- find the problem first ( which can be hard to do with out a running bike and an oscelliscope)
good luck