Help Magneto Points Burning Up

[rla442]

My little putting around tractor, an early Case VAC with a magneto keeps burning up the points in the mag. When the points are cleaned I can start the tractor by the hand crank on the second stroke. The problem is after running the tractor for about an hour it will start missing and once its shut down, it will not restart because no spark. I'm getting tired of pulling the points out of the mag and stoning them. The points are actually burnt to a point they need stoned after just a short time of running.
I've replaced the condenser with no change. Any ideas of why my points keep burning up after just an hour or less of running?

 

[Philip-TX]

I put an electronic ignition in my '59 Willys.

Pertronix has one for Case VAC
http://www.tractorpart.com/case_ignition_electronic.htm

 

[Bigfoot]

An electronic ignition is a nice upgrade on any tractor with points.

 

[Nesikep]

I'd try another condenser.. again!.. that's the part that prevents the points from burning, so I'd say you got a defective one.

I've put electronic ignitions on my Wisconsin V465, my Leyland 154 tractor, and others because I got sick of it too... Of course they all have batteries to run the electronic ignitions as well.

 

[rla442]

I'll try a new condenser and see what results I get. I've run points in my old cars with no problems but this tractor will sure make you cuss. I'd like to fix the mag since I'm not prepared to spend the money on it to convert it over to a distributer. The Case VAC tractors aren't worth a whole lot of money but are functional for a small going to the woods for firewood tractor or plowing the driveway in the winter time. Its a 1946 model and came with a mag instead of a distributor like the later versions. Converting it over to a distributor is probably going to cost about half of what the tractors worth.

I was just wondering if the coil in the mag could be too hot.

 

[hurleyjd]

Reread his post it is a magneto I am not aware of any electronic points conversion for a magneto.

 

[Nesikep]

Can you send a picture of the magneto? I know of a gut who has a PILE of them.. might even have the same one

 

[rla442]

Can you send a picture of the magneto? I know of a gut who has a PILE of them.. might even have the same one

The magneto is a Fairbanks Morse J4B3A. Just your basic 4 cylinder mag. I have 2 of them and the one doesn't stay in time and the one currently on it (the replacement of the one that doesn't stay timed) burns points like you crazy. I've changed condensers and still burn points up is why I wonder about the coil being too hot. Changing the coil in these mags is a pain since the screws the use almost never come out without drilling them out.

 

[Nesikep]

Strange why one doesn't stay in time... Can you swap the coil from one to the other? Lots of penetrating oil and let it sit for a bit, and use a GOOD screwdriver the first time around unless it's been pre-stripped for you.

I know I have a similar unit on an IH cub.. it's ancient like all of them, and it was in miserable shape when I got it, but with a bit of clean-up it works alright

 

[lavacarancher]

I'll run this up the flagpole for your enjoyment. Filing or stoning points should only be done in a pinch. Once the points get pitted, filing them only makes the problem worse in the short term. Points (new) are polished mirror shiny and given the correct capacitor (condenser) they will last a very long time. Filing makes the surface on the points rough and puts hundreds of of potential arc spots on the surface. It only takes one spot to arc and "weld" the points shut or deposit oxides of silver (usually) where they won't make electrical connection.

Try replacing the points AND condenser with new ones and see if that doesn't fix your problem. Oh, one more thing. Make sure the new points don't have any oil residue on them. Wipe them clean with a soft paper towel.