SH won't start

Va Gasman · Oct 19, 2013

3 weeks ago I was on a 29 mile tractor ride thru the country side. Everything went fine. But afterwards I noticed the tractor was cranking longer to start. Usually starts on the first bump. Then it got to 3-4 seconds of cranking. Now it won't start at all. I reset points and see I have fire across points. But there is no spark at plugs. recently changed this to 12v w/ alternator w/resistor and has been fine. What should I look for next? I was going to get new points and condenser for starters.
thanks, randy

gene bender · Oct 20, 2013

If you have fire at the points must have a fuel problem. When you remove a plug and then ground it there should be fire unless rotor or cap is bad

El Toro · Oct 20, 2013

I would get a new rotor. Hal

Tom Fleming · Oct 20, 2013

Sounds suspiciously like a coil. spark at the points still hasn't gone through the coil yet (it makes the coil spark). Spark at the points and none at the plugs can be one of a couple of things:

1. rotor
2. cap
3. wires
4. coil

Since you changed to 12v system, did you change out to a 12v coil? If not, did you provide a resistor for the coil? If not, you may have cooked it. If you did swap out the coil for a 12v, it also could have just flat out failed.

Va Gasman · Oct 20, 2013

All the ignition parts are less than 40 hours old in the field. there is fire at the points but nothing at #1 or #4 spark plug when removed and grounded. When I changed to 12V I did add the supplied resistor.
I guess I will pursue replacing the coil w/12v. Any thoughts... let me know.

Tom Fleming · Oct 20, 2013

Not often, but a few times I have had new components fail shortly after installation. I am not saying 100% it is your coil, but it sure sounds as if it a likely candidate. Do you have the old coil? You could use that to test.

John G. Hasler · Oct 20, 2013

Check for spark at the wire from the coil to the cap.

ken house · Oct 20, 2013

replace coil wire

El Toro · Oct 20, 2013

Look closely at your cap to see if there's any cracks. You could swap one of the plug wires that fire to one that doesn't fire to rule out the plug wires. Hal

Janicholson · Oct 20, 2013

Put a different coil on it (easy and if you have one it is free) if it runs then, you know the coil has gone to the recycling bin. They do die like that. a second check is to take the coil wire and hold it with a dry wooden or plastic cloths pin about 1/4" from the block. If no fire there, I would go with the coil swap. A 6v coil will work with the resistor, a 12v for use with an external resistor is also fine with the resistor. A 12 volt coil with no resistor required is ok if you bypass the resistor with a jumper. Jim

the tractor vet · Oct 20, 2013

(1) i have had better luck usen a 6 volt coil with a resistor , did you reverse polarity on the coil when you made the switch from 6 volt to 12 and i assume that you went neg. ground with the 12 volt ya have to switch the coil around .

IlliniJohn · Oct 20, 2013

I bought an M that had been driven into the shed and parked for 4 years - -then would not start.
Points were good, sparked thru coil, had spark at end of spark plug wires, But would not fire through any of the plugs - -I have no idea as to why.

Replaced plugs, and it has started at 1/4 turn for the last 6 years (though I rarely use it).

Best Wishes,
John

SH won't start

Va Gasman

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gene bender

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El Toro

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Tom Fleming

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Va Gasman

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Tom Fleming

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John G. Hasler

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ken house

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El Toro

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Janicholson

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the tractor vet

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IlliniJohn

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