Went to start the bike today and it lit off then died. Wouldn't lite off anymore. Turn off the key and wait a few minutes. Try to start again and will lite off the first time then die. The battery was weak so I had the battery attached to a jump box if that makes any difference. I took the carb off and cleaned it to make sure. Checked spark doing the spark plug against metal trick and it has spark. I sprayed some carb cleaner into the intake and it lit off then wouldn't lite anymore. It has fuel and is clean from what I can tell. Any suggestions? I don't have a service manual but sure would appreciate one if someone could send me an electronic one.

 

Okay, so tried a different cdi box and still no luck. Stator and flywheel look fine and stator seemed to test fine. Tested the ignition coil and tested fine. First time I checked spark it sparked then would stop. Put a screw driver up to it and would spark constantly. Took boot off and held wire to the cylinder and sparked constantly while cranking. Tried new spark plug and now won’t spark at all. Tried a spark plug boot that I know works and still no spark. I’m at a lose.

 

Symptoms are a bit like the "loose magnet syndrome" but I assume you have had the alternator case off as you write "Stator and flywheel look fine". Now the fault is "on" check the exciter coil and trigger coil are both sending AC volts to the CDI when you spin the starter. Check if the CDI is sending high voltage pulses to the HT coil, and if it won't spark with a new plug, try refitting the old one.

 

How do I check those things exactly? I don’t have a manual and not sure what all the readings/wires to check should be.

 

do simple things first....unplug all electric al connections, spray the inside with WD40..reconnect....then retest.

 

If you expect to do this work yourself, then you will need a service manual and other tools to get the job done. If you not willing to buy what is needed then take it to a professional. You can keep guessing and swapping parts and hope you might find a solution but you wont get much riding done.

 

Thank you all but I got it going. I replaced the battery and the brushes in the starter and it started right up. I can’t explain how or why but it runs again.