DSMason

New User
I am looking for help getting my rebuilt 1941 John Deere B running properly (or at all now!). I bought a rebuilt magneto in 2010 but never got the tractor running very well so I rebuilt the carburetor. No difference. Still running rough, backfires, one cylinder only, etc. Carb has gas, float level is good, but now NO spark at all.
The tractor has been in a dry shed for the last few years and the new magneto is still new, never been wet or anything but seems to produce no spark either on the tractor or on the bench. Points gap is .015 as specified, it is a Wico X.
I've about had it with magnetos! Does anyone know what is wrong?
Does the "rebuilt distributor" #1111558 from this company convert these tractors to coil and points ignition?
Thanks so much,
Dave
 
Stick with the magneto. Also, the best way to determine if it is the fuel system is take tube off ait intake end of carb and squirt fuel in while turning over. It will at least fire/start/ and burn out what you sprayed in , even if the carb was totally junk. Are you talking "NEW" mag or re-built ?
 
And make sure the plug wires are installed correctly top terminal on mag goes to #1 (left). And throw the Champion plugs
away
 
As Ollie says, maybe a bad condenser, but when they sit for a period of time, even inside, the points get a "coating" on them. Clean, and reset the points. (many times I have just ran a dollar bill between them a few times to clean them off.
 
If as you say it's been rebuilt, the points are likely not worn at all. As others have said the points likely have a film on them! Clean them until they are shiny clean. You likely don't need to file them but just to polish them shiny clean. The dollar bill trick may do the job but I'm guessing it may take a bit more than a few swipes of Uncle Sam's paper!

I never use sand paper or emery cloth. I believe it leaves embedded grit in place. Think of how a jack stand's foot looks after you drag it across concrete having forgotten to fold the jack up. Sandpaper does the same thing to points but on a microscopic level & sand paper grit is not a good electrical conductor!

One of my favorites is a clean but dull file. Removes the film & oxides but not metal. Then a buffing wheel followed by a clean cloth & some solvent like brake cleaner, carb cleaner or ether. If nothing else, rub them hard on the end grain of a piece of clean hardwood. Don't be gentle. Put decent pressure on them one point at a time with one finger on the back of the point using the other hand to run the mating surface back and forth hard across the end grain. Do that until you feel them get warm! Make sure nothing is stuck to them. I shoot 'em with carb cleaner or ether wiping with a clean cotton cloth then put 'em back in.

Gap them carefully. Remember, the resistance and especially the gap are way more important to a magneto than an electric distributor! I've seen your predicament many times. The mag was just re-built two years ago & hasn't been used at all! Been on the highest shelf in the clean dry shop. Still when not being used they grow a white or gray layer of something (I don't know what) on them & she will no make sparks! It's almost always the points!

Someone mentioned throwing the Champion plugs away. If they're D16 plugs I'd agree. Even Champion does not recommend those for the letter series Deere tractor! If you're anywhere near stock you'll have to be well tuned (lean), keep the temperature up (working shutters) and work the tractor HARD to keep a D16 from fouling. Not because it's junk but because it's simply the wrong part! They're just not made for each other and so will give you headaches! Use the D21 for normal service or D23 for light service.

No I do NOT work for Champion Spark Plug but I do hope this is helpful.
 
I agree with everyone on the dirty points. Almost every tractor I have needs points cleaned after sitting. Always start with cheapest and easiest first. Condenser would be my 2nd step.
 
wow! So impressed with the response from everyone. Tractor is running!!! Points are sanded with emory, though. I'll polish them once I get some other issues dealt with.
I've got a hydraulic pump to mount behind the mag so I'll have it out again anyway.
Many sincere thanks for these posts, made my day!
Dave
 

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