Weak spark on Cub Lowboy

Richard G. · Dec 16, 2014

Worked on a Lowboy yesterday for a fellow. 6 volt system, strong battery, spins fast, but very week spark. I got it to fire off using a 12 volt jump with the 6 volt battery disconnected. He had put in new points, condenser. The coil he bought was a round can coil, but does not say if it is 6 or 12. No name on the coil.
If it is 12, would that make the spark weak on a 6 volt system?
Also, on a positive ground system, does the hot wire from the switch go to the + or - on the coil?
Thanks, Richard in NW SC

Nebraska Cowman · Dec 16, 2014

Easy way to remember how to hook up the coil is remember that the points are doing the grounding.

old · Dec 16, 2014

+ ground means + to the points. As for spark if it is in fact a true 12 volt coil yes spark would be weak on a 6 volt battery but unless he or some one else replaced the coil it is likely to be 6 volt coil. Try putting the old condenser back in. Now days it is common to get a new bad condenser. Also make sure the points are set to the correct gap

Richard G. · Dec 16, 2014

Old, We tried the old condenser. No change. The coil is one that he bought but is not sure what it is. I did set the points.
The old coil was tried also but I found oil leaking out of it. It looked like an original IH coil. It did the same with it on the tractor.
Richard

John T · Dec 16, 2014

"If it is 12, would that make the spark weak on a 6 volt system?"

YES If you apply 6 volts to a 12 volt coil the spark will be weak

"Also, on a positive ground system, does the hot wire from the switch go to the + or - on the coil?"

Input from ignition switch to - coil terminal and + of coil to ground (via closed distributor points) for a Pos ground tractor.

John T

Richard G. · Dec 16, 2014

Thanks for the replies fellows.
Richard in NW SC

old · Dec 16, 2014

Do you have a spark at the point when you open and close them by hand?? If you do not then the points are dirty or the coil is bad. Maybe the ignition switch is bad which will also cause that

Richard G. · Dec 16, 2014

Old, the spark was so weak you could barely see it.
He ordered new points, condenser and correct coil today. Will respond with the results.
Thanks Richard

old · Dec 17, 2014

I would try to hot wire it before throwing parts at it.

Weak spark on Cub Lowboy

Richard G.

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Nebraska Cowman

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old

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Richard G.

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John T

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Richard G.

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old

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Richard G.

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old

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