By
RGS
1989 Moto 4 YFM350ERW intermittent spark.
Quad has set for about 7 years and was running when parked. When I replaced the battery and attempted to start it had no spark.
What I have done. Followed troubleshooting in the manual.
1. Coil failed the resistance check so I replaced it. Still no spark.
2. I performed resistance checks on the stator and they all pass.
3. Found a bad rear brake stop switch and unplugged it and connected the wires in order to disable. Now I have intermittent spark. I believe that the issue is with either the stator or CDI and not sure which.
1989 seems to be a transition year for electrical. I can get new aftermarket CDI units for 87-88 and 90-94. I cannot get ones for a 89. I can get new stators for 87-89 and 90-95. Looking at the schematics the wiring on my moto is closer to the 90 ones on the ATV side of the CDI and closer to the 87-88 on the stator side of the CDI. Looking at part supply sources the stator housing is the same part # for all the years and looking at some of the stators on Amazon that have the dimensions on them both of the stators are the same size.
What I am thinking of doing is to replace the stator and CDI with a 90-95 one as these parts are all readily available. Does anyone know if this has been tried before and if there are any issues with doing this.
As a side note I also have a 1993 Moto 4 YFM350ER that has been sitting longer but it is located about 400 miles from me at this time. By doing this change in addition to being able to get parts I will also have 2 ATV’s that are the same electrically.
By RGS
By wanrep
By Thekevinjb
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