# Big Bear - Weird spark issue



## motox88 (Mar 20, 2012)

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! :banghead:


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## NMKawierider (Apr 11, 2009)

Bad spark plug or low coil power causes this.


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## motox88 (Mar 20, 2012)

thanks for the reply!

So I need to look deeper into the ECU/Stator/pickup/regulator?
Spark plug is new.


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## NMKawierider (Apr 11, 2009)

motox88 said:


> thanks for the reply!
> 
> So I need to look deeper into the ECU/Stator/pickup/regulator?
> Spark plug is new.


Stator and pickup. Does the bear use a magneto to generate the spark? I forget. or just battery power? If it does have a magneto, then check that no coil touches the magnets. If you see a spot that is, you will have a loose main bearing but if adjustable, give it a few thousands more


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## motox88 (Mar 20, 2012)

Nothing is really adjustable. I could shim the pickup but the would only give lateral adjustment. It's fixed with respect to pickup gap to flywheel.

I've never thought about a crank bearing causing the issue though. Not sure how I'd be able to verify w/o taking more apart. I will take the case off again and check the stator/flywheel for marks although I don't think this is the issue.


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## NMKawierider (Apr 11, 2009)

Maybe see if the pickup has any marks on it. You can also grab the flywheel and pickup on it to see if you feel any movement. It won't be much but any that you can feel is bad.


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## motox88 (Mar 20, 2012)

As it turns out the plug on the stator side had two wires in the wrong place. I had to swap the Red and Blue/w white in the stator plug. Now it sparks!

As it turns out these wires are for the rotor rotation detection and why I was only seeing spark when the motor was rocking backwards.

I guess that's what I get for buying a cheap stator off ebay.


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## catman3516 (Dec 15, 2013)

as long as you figured it out, and get back to wheeling who cares were the part came from.

I boiught many an ebay part with no probs---knock on wood


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