Farmall F4 magneto issue

[junkpile]

I have a 36 f12 with f4 magneto. Sat for years and I was getting no spark. Installed new coil, points, and condenser and placed magnet on neodymium magnets to charge as described in 2022 gas engine article. Still no spark when on tractor. Impulse appears to function properly. If I take off, disengage impulse and spin, get spark with a little speed. Appreciate any advice on what to try next.

 

[560Dennis]

got spark on the benches ,then got spark on the tractor. Find out where timing is.
You got a blue ribbon magneto manual? In it is all about the F4 . They have them online on cub forums under Rudy.

 

[Fritz Maurer]

When installed on the tractor, make sure the spark advance control is not positioning it in the "off" position. Check to make sure the primary wire is not pinched to ground behind the point plate with spark advance cover installed.

 

[junkpile]

I've been setting advance about halfway so don't think it's grounding. I'll check primary wire. Could magnet still be weak?

 

[used red MN]

I've been setting advance about halfway so don't think it's grounding. I'll check primary wire. Could magnet still be weak?

Hello junkpile, welcome to YT! A resident magneto repairman said if the magnet will hold itself to a vertical metal surface in all possible positions it should have adequate magnetism.

 

[martinautry]

If I understand correctly, if you spin without the impulse you get a spark. Add the impulse, no spark. If this is true, it sounds like the magneto gear timing may be off. If you possibly took the rotor tower loose when removing the coil, a gear could have slipped a few teeth. Just check to see if the dot on the cap rotor gear still aligns with the dot or beveled edges of the lower mag gear. Just a thought.

 

[junkpile]

You called it martinautry. Timing was off when I replaced coil. Firing well now. Thanks to all for help. Does anybody know someone interested in selling brake shoes that fit an f12?

 

[Fritz Maurer]

If you got them off without breaking them, you can get relining kits from Rice Equipment Clarion, PA.

If they are seized on the hinge pin, DO NOT pound or pry on them. They are robust enough to be brakes, but a little on the delicate side, especially if heavily rusted and pitted.

You need a torch to heat the eye of the shoe. Once you get it wiggling, your penetrating oil will work much faster and you'll have it off in no time.

 

[junkpile]

All I have is what's left on the pin and o e broken shoe. I do have the drums and covers but no shoes.

 

[560Dennis]

I send may Farmall C Brake shoes to Cook Bonding in Cleveland to be relined. Work fine stopping load on hill .
For a C I can get cheaper Chinese brake shoes . But I don’t want them. Rather patronize the local people.