Distributor not turning on 1948 JD B

Mike Burgan

New User
Morning folks, I have a 1948 John Deere B. When I tried to start the tractor yesterday, it fired once, and then nothing. It ran fine the last time I used it to push snow two weeks ago (its main use). Didn't sound like it was getting spark, so I pulled distributor cab. When I turned the motor over, the rotor only turned a little bit - engine cracked over 10 times or so and rotor turned maybe 1/4 turn. Where the motor is, and with the distributor cap off, you can turn the rotor backwards by hand about a 1/4. You cannot turn the rotor by hand forward. I also took the governor cover off above the flywheel. Three of the ball bearings were out of their cage. They were stuck to bearing grease on the governor end cap. I did not see any obvious damage to the race on the end of the governor shaft. I was able to pull the cages the ball bearings ride in out of the race it rides in, so I assume it is shot and will be replacing it (New Departure #909601). I did not see anything else that was obviously broken in that end of the governor. What else should I look for? The governor gears were meshed with the gears on the flywheel (or crack shaft if that is what they are meshed with). But I did not try to turn it over to see if the timing marks were still lined up. Would the bad bearing cause the governor to not turn the distributor (seems unlikely to me). Or is the problem more likely with the WICO magneto (model X)? Any recommendations on who can rebuild the magneto in north Idaho/eastern WA, or elsewhere that I can ship it to? Thanks for your help in advance! I need to get this thing going. It is the main thing we use for snow removal, and we have a month or two of winter left!
 
If the bearing is shot it may let the shaft move far enough to not engage the magneto drive. Take the mag off & get the bearing fixed. If the mag is good Put it back in time & it should be good to go.
 
From what I remember the last time I took my magneto off you should be able to take it off and turn just the mag itself and try to turn the shaft it locks to if the shaft in the governor moves you probably will have more wrong in your governor not much can go wrong with the mag it is a half shaft with a nut that holds it unless the nut in the back of it came off witch would be visible if you took the mag off
 
teddy52food, I put the bearing back together and replaced the governor cover plate (with the magneto off as per Pete in MD). That tightened everything up, and I could not turn the shaft on the magneto side. I'll get the bearing replaced and see if that fixes the problem. As for the magneto, the nut was tight and it spins fine. Looks like the bad bearing could have been the issue. I still have a couple questions about the magneto. First, what color should the spark be if you hold a plug wire to the frame. Mine is a pale yellow. Shouldn't it be bright blue? I've had the tractor for 7 years, and it runs okay, but seems like the spark is weak. Does anyone have experience with Mainely Magneto's, sponsors of Meli's Tractor School. Do they do good work? Any recommendation on who else I could send it to for checking/rebuilding if I decide to go that route? Finally, I've spun the magneto several times checking it. Looks like I have a 50/50 chance of getting it back in the correct timing sequence. It will either be right, or 180 degrees off correct? Are there any timing marks to help line it up? Thanks, Mike
 
Seams like a weak spark mine is blue i only replaced the spring, condensor, points and rotor on mine if I remember the timing marks are on the flywheel I believe I think it was a post on here that talked about timing a b that I read and did mine
 
The shaft that drives the magneto will only turn with the engine when it is right. You can send the mag to me if you wish. I have been working on them since the 60's. I have the coil & condenser testers and a magnet charger.
 
I finally had time to work on the tractor and figured out what the problem was. I pulled the flywheel cover off so I could make sure the timing was right when putting the governor back on. The splines on the flywheel are all sheered off. So when you push the starter button, the starter will engage, and the flywheel would just spin around the crankshaft. Sometimes it would catch the crankshaft enough to move the crankshaft enough to move the governor and the distributor. Splines on the crankshaft appear to be fine. Anyone have a flywheel for 1948 John Deere B, part number B2461R, with good splines you'd want to sell?
 

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