Engine won't start

[israel_ny]

everything worked fine, engine ran smooth for the first 10-20 miles until my back wheel got a little loose.. after strengthening the bolts super tight i couldn't get the engine to run again... it won't start.. I checked all of the wires and the connections and found out that a few copper fibers in the black wire that's coming out of the CDI are black... maybe it burned out.. should i try to replace the CDI? or could it also be associated with the magneto?

Thanks in advance

 

[Al.Fisherman]

everything worked fine, engine ran smooth for the first 10-20 miles until my back wheel got a little loose.. after strengthening the bolts super tight i couldn't get the engine to run again... it won't start.. I checked all of the wires and the connections and found out that a few copper fibers in the black wire that's coming out of the CDI are black... maybe it burned out.. should i try to replace the CDI? or could it also be associated with the magneto?

Thanks in advance

Sounds like you somehow toasted the CDI and it was just a coincidence that it happened at that time. First check the wires coming out of the magneto to make sure there is no short. Then before replacing the CDI check the voltage from the magneto..it should be somewhere around 7.5 volts.

 

[AussieSteve]

Otherwise, copper wires turn black when exposed to (excess) moisture. Don't ignore this possibility.
Also, if you have a DMM, the blue winding should measure a couple of hundred ohms and the white winding should measure about 2 ohms.
And have you checked for spark at the plug?

 

[israel_ny]

i found out that some water got into the magneto and changed both CDI and magneto
thanks everybody for your help