Working on my '49 B yesterday. I've got some starter issues I'm working on (bendix keeps kicking out). Anyway, it sat outside for a few days and it got rained on one night. Not an issue to me but some people like to keep them in or have the mag covered. So I started it up and could tell it wasn't running right. I pulled the top mag wire and no change in the way it ran. Pulled the bottom wire off and it wanted to die on me. So I'm assuming it's not firing on the right side!? Figured the mag probably got wet and has a problem. But when I went to pull the plug boot off I got a shock through a crack in the boot...it's not the correct right angle boot and its cracked where it's kinked. So, I've got juice there. Put an inline test light between the plug connection and the plug and the mag appears to be firing OK. So I thought maybe I had a bad plug...took both plugs out, cleaned them, but when I put them back in I swapped them out side to side. Still no change on the right side when I pull the mag wire. Am I looking at things correctly here?? Any thoughts? I will replace the plugs/plug wires anyway.
- Thread starter GregoryU
- Start date
Mike(NEOhio)
Well-known Member
- Location
- Newbury, Ohio
It's not firing on the LEFT side. Try pulling the wire off the plug and holding it about an inch from the plug tip. I've seen run better that way since it builds higher voltage to jump the larger gap. Then it's probably the plug.
Loosehandle
Well-known Member
- Location
- Wisconsin
Top wire goes to left side, sounds like your spark is weak. Are you sure you have a magneto and not the distributor that looks like one?
The reason I thought the top was the right was when I took the right plug boot off to put the inline test light on there was no change in the way the tractor ran. As far as the mag/distributor thing...I have no idea, I haven't taken anything apart yet. And, my knowledge of JD B's is minimal until my book gets here.
Watthour
Member
I don't know how THAT could ever happen. Those valves hardly ever stick, do they?
Attachments
greenmech
Well-known Member
- Location
- Lakeville MN
Test your spark from each terminal on the mag to ground, that will rule out if the mag is OK. Sometimes the cap gets corroded and will not fire. If you got fire to both sides it may be a carb issue. Hope this helps. Ron MN
Mike(NEOhio)
Well-known Member
- Location
- Newbury, Ohio
Get the mag timed right and you should be good to go. Make sure the forked rotor is in position to fire the top terminal first when you put the mag back on.
Fixingfarmer
Well-known Member
#1 I think you are close to finding the problem. Make yourself a spark plug wire to test with both now and in the future and run it to the other side it’s NOT worth pulling it out of the tube to switch just for a test imo. I check with new plugs on these for gosh sakes they only have 2 it is worth the 8 dollars on these small ones to have them be new. The older big ones where they are 17 a piece sure. You have said the wire is in poor condition since it zapped you that can be true or false I’ve had it arc enough to start a carb fire pumping gas out a cylinder spark plug hole after flooding before 3 inches away from metal not attached to a plug. Pull the plug out see if you have spark with it grounding on the frame FUEL OFF!
#2 The rockers can also be stuck for awhile and not broken. Bent pushrods. Take the tractor outside pull the cover you can crank without starting if you had a good starter or just start and run it a minute and make sure both sides are operating good and good in this case means visually the same since one is working. There will be a bit of an oil mess usually it will be somewhat contained at idle but it will be worth it. Incredibly common to have problems with this. Here’s a picture of the g rocker that was this summers 2 cylinder rocker arm failure for me.
#3 an intake manifold gasket leaking bad enough can also cause this issue. Cracked manifolds are also common. One way to test is does it get a bit better with ether sprayed in? You can spray along the outside of a cold engine manifold as well and see if you can find a crack but I’ve found that a 2 cylinder this works only sometimes. If you spray into the carburetor and it gets better that’s the best way to check. Repeat with someone else pulling your mag to plug wire like you have been doing while spraying a bit if you think it got better and you will have your answer. The ether vapor will make it in easier than the gas. Be sure to do this part with the valve cover back on as rpm might fluctuate up a bit. No reason to get yourself covered in oil.
4.Then go down the mag issue road if absolutely none of this helped. You are correct it is a possibility it’s a good excuse for another wico x magneto tractor to test!
#2 The rockers can also be stuck for awhile and not broken. Bent pushrods. Take the tractor outside pull the cover you can crank without starting if you had a good starter or just start and run it a minute and make sure both sides are operating good and good in this case means visually the same since one is working. There will be a bit of an oil mess usually it will be somewhat contained at idle but it will be worth it. Incredibly common to have problems with this. Here’s a picture of the g rocker that was this summers 2 cylinder rocker arm failure for me.
#3 an intake manifold gasket leaking bad enough can also cause this issue. Cracked manifolds are also common. One way to test is does it get a bit better with ether sprayed in? You can spray along the outside of a cold engine manifold as well and see if you can find a crack but I’ve found that a 2 cylinder this works only sometimes. If you spray into the carburetor and it gets better that’s the best way to check. Repeat with someone else pulling your mag to plug wire like you have been doing while spraying a bit if you think it got better and you will have your answer. The ether vapor will make it in easier than the gas. Be sure to do this part with the valve cover back on as rpm might fluctuate up a bit. No reason to get yourself covered in oil.
4.Then go down the mag issue road if absolutely none of this helped. You are correct it is a possibility it’s a good excuse for another wico x magneto tractor to test!
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