Hello all. Put new motor in atv from 90cc to 125 cc. Tried matching wire colors coming out of new motor stator to existing wire harness. New motor has two yellow wires while existing harness has one white and one yellow. I arbitrarily connected yellow to yellow and remaining yellow to white. Other three match, red/ black, blue/white and green. I used crimp connectors to connect wires. I had spark but not anymoremore. Put new cdi box and new ignition coil but no change. Tried different new spark plug still nothing. Any ideas , experience can share what can or what to try?

 

Do the help diagnose stator tests in the Chinese engines section of this forum.

You don't even need the yellows connected to get a spark, as they are for the charging circuit. Worth checking if those wires are earthed though, as some two wire stators are single phase so won't be earthed, some are three phase but use earth for the third phase so yellow wires would be earthed. You can't fit a single phase stator to a bike set up for three phase, but that won't affect spark, unless new stator got so hot it burnt out the sparking (power) coil as well.

 

Ok thanks. I found thread about "help diagnose a stator" but the cdi box pictured is not like mine. Not sure of this situation will be like mine.

 

The sparking power (coil) you referring to is in the stator itself or you referring to spark plug coil? Thanks

 

Power coil is on the stator, it is the one the black/red goes to. Usually shaped and /coloured slightly different to the other coils. The trigger coil is usually on the outside of the flywheel and the blue/white goes to it. You can do the tests using the wire colours as a guide, pinouts on CDIs differ anyway, earth is the most important, get that wrong and you can blow the CDI.