John Deere B with low spark at points

littleredb · Mar 23, 2020

I recently purchased a 1952 John Deere B at auction. The tractor did not run. Its electric start.I replaced the battery, points and condenser and installed a new coil. I can see no spark at the points when trying to start the tractor, but if I put a screwdriver near the points when trying to start the tractor I can see a faint spark. I was wondering what would be the cause of this?

rustred · Mar 23, 2020

put the oil condenser back in. also did you clean the point contacts , new points need to be cleaned. opening the points with your screw driver should produce a distinct spark snap when all is good.

rustred · Mar 23, 2020

put old condenser back in.

old · Mar 23, 2020

Many points now days come with a coating on them that needs to be cleaned off. If you still have the box the points came in rip a flap off the box fold in in half and run the ruff side between the points a number of time that try the spark test. If still not good put the old condenser back in since now days you have a 50/50 chance the new condenser will be bad

steve_in_mo · Mar 23, 2020

What all the others said, but I used a paper towel soaked in acetone to clean the points.
The old condenser was bad but the new one (fortunately) worked.

Deere Mark · Mar 23, 2020

"no spark at the points" ?????????????????? The purpose of the ignition system is to produce a healthy spark at the spark plugs. You should be checking for spark at the plugs or at the output of the coil. There is not supposed to be much of a spark at the points ever. If there was spark at the points, it would soon cause pitting of the points. The purpose of the condenser is to prevent sparking at the points. If the condenser was bad or missing, you could expect "sparking at the points".

littleredb · Mar 23, 2020

Did clean the points with paper and put the old condenser back in. I have no fire at the plugs. The old plugs were a champion D21. Is this the correct plug? I was told it should be a champion D16. Should I also replace the distributer cap at this time?

old · Mar 23, 2020

Is this a distributor or a mag?? If it is a distributor remove the ignition side wire off the coil and make sure the points are closed. Then turn on the ignition. Now touch the wire back on the coil and off again a few times. You should see a small spark when you do that. If no spark you either do not have power at the wire or the points are still dirty. So if no spark try a hot wire. Take a wire from the ignition side of the battery and then touch it to the ignition of the coil on and off a couple time with points closed. Again you should see a small spark. You can also at the same time take the coil wire out of the cap and hold it say a 1/4 inch from the block. Every time you u remove the wire from the coil you u should get a blue/white spark that jumps a 1/4 inch gap or more

Bob · Mar 23, 2020

(quoted from post at 13:40:25 03/23/20) I recently purchased a 1952 John Deere B at auction. The tractor did not run. Its electric start.I replaced the battery, points and condenser and installed a new coil. I can see no spark at the points when trying to start the tractor, but if I put a screwdriver near the points when trying to start the tractor I can see a faint spark. I was wondering what would be the cause of this?

Let's start at the beginning, 6 Volt or 12 Volt battery being used?

(Was built 6 Volt, someone may have converted it to 12 Volt in the ensuing 68 years.)

Coil make and part number?

Any resistors ahead of the coil that may have been added by a P.O.?

old · Mar 23, 2020

Yes there should be small spark at the points if you open them by hand but only a small spark

littleredb · Mar 23, 2020

It has a distributor with a 6 volt battery. I found no resisters. The coil was bought from yesterday Tractors part #D4PE12029AA. Will be trying the hot wire as suggested by OLD.

old · Mar 23, 2020

I have found that some of the simplest trouble shootign methods also work the best. That is why I say try the hot wire and spark test

old · Mar 23, 2020

I left out the 2nd part of the spark at coil test.
If you have a spark with the points closed the turn the engine to the point that the points are open and do the spark test again. You should not get a spark and if you do you have something shorted out

620 John · Mar 23, 2020

Bad condenser out of the box??? Wouldn't be the first time. Condenser has good ground?? Distributor has a good ground back to battery??? Point's oxidized or oily out of the box?? High resistance in key switch?? Just thinking out loud. First check simple things already mentioned.

David G · Mar 23, 2020

You should have very little spark at the points if condenser working.

Are you talking spark out of the coil?

fixerupper · Mar 23, 2020

D21 plugs are hotter and about right for light or moderate loads using todays gasoline. D16s were the proper plug for back in the day when your B pulled a plow all day all week long. And yes, it will run just fine on Champions.

PJH · Mar 24, 2020

I had a distributor rotor go bad one time that acted like that. If you hold the coil wire close to the rotor tab as you crank the engine over, it should NOT jump spark to the rotor.

littleredb · Mar 25, 2020

Tractor still will not start. I have spark at the plugs and gas is misting out of the plug hoes when I turn the tractor over. The tractor does not even try to start.

JMOR · Mar 25, 2020

(quoted from post at 13:08:40 03/25/20) Tractor still will not start. I have spark at the plugs and gas is misting out of the plug hoes when I turn the tractor over. The tractor does not even try to start.

aybe low compression?

jimtrs · Mar 25, 2020

(quoted from post at 13:08:40 03/25/20) Tractor still will not start. I have spark at the plugs and gas is misting out of the plug hoes when I turn the tractor over. The tractor does not even try to start.

Spark Plug wires timed correctly?

Rich'sToys · Mar 25, 2020

(quoted from post at 12:08:40 03/25/20) Tractor still will not start. I have spark at the plugs and gas is misting out of the plug hoes when I turn the tractor over. The tractor does not even try to start.

Is it flooded? Try hooking a chain onto it and give it a pull.

John Deere B with low spark at points

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