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2001 Yamaha Big Bear 400 - Spark Issue


motox88

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This has been a frustrating one to figure out, but long story short I've replaced just about every component on the machine and I'm still not getting spark. Or at least not how it suppose to work...

When the engine is turning over it does not spark at all, but sometimes when I let off on the start button it will spark just once. I've played with this numerous times and it will only generate a spark like this. I've seemed to somehow come to the conclusion that this correlates to the engine or crank "rocking" backwards. Depending on where it is in the stroke the crank will rotate back in the opposite direction when the starter motor dis-engages.

I thought maybe I had a polarity problem, but this is where I'm stuck. If it is indeed a polarity problem what could cause it?

If it's not a polarity problem is it just categorized as a "weak" spark issue?

Everything seems to ohm out fine, continuity checks at each plug check out, etc, etc....

Throw me some ideas. PLEASE!

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well, on mine, there were 2 wires coming out of the engine, a red and white with a connector on the end. when the connection was met, the wires are red to red, white to white, i was told to switch the wires and after i did, i had spark ... maybe a longshot but worth a try ... did your instructions say anything about switching the wires?

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  • 1 year later...

I replaced my stator and put the cover on it, started right up. However the gear shift lever will not move. I attached two pics of both the crankcase and crankcase cover. In the pic with crankcase cover there is on item I am pointing at with a screwdriver. It looks like a deformed fork with two fingers. What orientation is that supposed to be when closing the case?? byter1 at gmail.com for direct emails.

Stator Finger direction.jpg

Crank Left Side.jpg

57d7734c2a7d7_StatorFingerdirection.jpg.c93a6b6eb6a053a4d6195b0692bb7b6c.jpg

57d7734c2cee9_CrankLeftSide.jpg.a996ab0f570566b72e769a17ce5ae0f5.jpg

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