# Gravely 7.6 L problem



## pete1 (Jun 13, 2012)

I'm not getting spark. It has a WICO mag. Condenseer, points & continuety through plug are all good. I reset the timimg acording to the book so I believe it's OK. I don't know what the mag should put out or if it is. Don't know what the coil resistance readings should be or how to test it for short under load. Need info and advice. 
Thanks,
Pete


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## Richard-tx (Jan 30, 2011)

The best I can offer is if you put new points and condenser in it and there is still no spark is the check the impulse mechanism. If there is no "snap" when the piston comes up on the compression stroke, then that is your problem.

The points has to be shiny clean. If they are a dull silver, then they are corroded and need to be cleaned. 600 grit sandpaper is what I use.

In the 30+ years that my father owned L/SC Gravely tractors, not once did the timing ever have to be adjusted.


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## pete1 (Jun 13, 2012)

*7.6 problems*

Thanks Richard. The points are clean and the impluse does snap when turned. Do you know what the Mag impulse output should be? 
Thanks,
Pete


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## Richard-tx (Jan 30, 2011)

The spark generated when it snaps should be at least 1/4" long. A 3/8" spark is quite common. If the kill terminal is properly insulated from ground then it likely needs a new coil.


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## Todd_W_White (Aug 12, 2011)

Magneto's lose magnetism over time due to age and heat. Even if your coil tests good (you have to use a special tester designed for the purpose, which I have), and your points are good and condenser tests good, it can still not fire, or be very weak, due to failing magnets.

The solution is to remagentize the Alnico magnets on the rotors. 

When I rebuild them for my customers, I now make it a practice of remagnetizing the magnets as part of the service. The difference in performance is AMAZING!

Once reassembled, the magneto needs to be recalibrated so that it will fire at the correct moment when the engine is running. On a Wico, this is possible. On a Fairbanks-Morse, it is not.


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## pete1 (Jun 13, 2012)

*Magneto magnet regeneration*



Todd_W_White said:


> Magneto's lose magnetism over time due to age and heat. Even if your coil tests good (you have to use a special tester designed for the purpose, which I have), and your points are good and condenser tests good, it can still not fire, or be very weak, due to failing magnets.
> 
> The solution is to remagentize the Alnico magnets on the rotors.
> 
> ...


Todd,
Thanks. I thought it would be the magnets or the coil but without being able to properly test left me guessing. The coil's continuous but that does not mean it's not breaking down under load. I have a contact for a working mag assembly for a very reasonable price. The guy just has parts, no ability to refurbish. Do you have a mag and would take my core to ofset cost? The mag I can get is $60 with no trade.
Thanks,
Pete
302-695-7611 before 2 PM easier to call and talk than type


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