Jd B running a little rough

jwitty

Member
So thankfully just barely got the tractor in the shed after it stalled. Driving it ran ok but stumbled a little. Shot flame once. I know it does need new wires. It is magneto ignition. Does it have points and if so how do I adjust them. And then, they guy put on a rubber fuel line with an inline fuel filter. Could this cause it to run bad? Thanks
 
Most of the time an in line filter cause more problem then it fixes. Me as long as the sediment bowl has the correct screen in it I would throw that in line filter as far from the tractor as I can. As for the points that depends on what mag is has. The mag on my B you just take the 4 hold down screw loose and the cap comes off and there is the rotor and points. You do know a JD 2 cylinder never runs real smooth that is one reason there called popping Johnnies
 
(quoted from post at 17:50:02 10/29/17) Most of the time an in line filter cause more problem then it fixes. Me as long as the sediment bowl has the correct screen in it I would throw that in line filter as far from the tractor as I can. As for the points that depends on what mag is has. The mag on my B you just take the 4 hold down screw loose and the cap comes off and there is the rotor and points. You do know a JD 2 cylinder never runs real smooth that is one reason there called popping Johnnies

Thanks for the info. Yeah I know they don't run beautifully this one just is hard to start sometimes and likes to die
 
It could be fuel starvation from a plugged filter. Disconnect the line downstream and be sure it's running out good. Hook back up and remove plug below where the line runs into the carb. Should run out good
there too. Just above that plug is a screen under the disc shaped cover held on by a bolt. If OK there, remove drain plug from bowl; should run out there good, but leave the plug out a minute or so to be
sure the stream doesn't thin out due to bad/stuck needle valve.

The mag does have points and condenser. Points adjust like any others, stock mag points gap to .015. If they look bad at all, best to replace them along with condenser. If points seem OK, consider
condenser. It can fail when hot, but start OK. So can coil in the mag. If it starts OK, but poops out when warmed up, suspect mag. You can find more in archive posts.

And it could be a valve that's leaking when hot. Probably not, but possible. But I'll guarantee the problem isn't your left rear tire being low. Other than that . . . .good luck! Maybe someone who knows
something about B's will post.
 
If choking it help it is a fuel problem. If it does not help could be a spark problem either one will make them hard o start. At least that one should have electric start. My B is hand start only so it can be a bear to start some times
 
Get new wires and then pull the plugs and check the color of the spark, it should be blue. If it is yellow you need to look at your mag but. Check the timing. But I'm thinking that from what you are saying, you probably need to go through you carb. Order the video from Roberts Carburetor Repair, best 20 bucks you will ever spend on your tractor.
 
"[b:654c4848f0][i:654c4848f0]<font color="#6699ff">It is magneto ignition. Does it have points and if so how do I adjust them.[/i:654c4848f0][/b:654c4848f0]</font>"

Yes, the magneto has points.

There are three types of magnetos for the Model B:

[b:654c4848f0]AB757R WICO MAGNETO (TYPE ?AP?)

AB2875R WICO MAGNETO (TYPE ?C?)

AA3870R WICO MAGNETO (TYPE "X")[/b:654c4848f0]

The two most common magnetos are the WICO X and WICO C.

Take a look at the [b:654c4848f0]AA3870R WICO MAGNETO (TYPE "X")[/b:654c4848f0] illustration below.

a176716.jpg" width="650"


Take a look at the photo below of the WICO X magneto.

a176717.jpg" width="650"


Take a look at the information from the [b:654c4848f0]Service Manual Electrical Systems SM-2029[/b:654c4848f0] in the [b:654c4848f0]Magneto Ignition Systems[/b:654c4848f0] section [i:654c4848f0][b:654c4848f0]Servicing Wico Type ?X? Magnetos[/b:654c4848f0][/i:654c4848f0] group under the [b:654c4848f0]ADJUSTING POINTS[/b:654c4848f0] paragraph on page 70-15-7.

a176718.jpg" width="650"


Take a look at the [b:654c4848f0]AB2875R WICO MAGNETO (TYPE ?C?)[/b:654c4848f0] illustration below.

a176720.jpg" width="650"


Take a look at the information from the [b:654c4848f0]Service Manual Electrical Systems SM-2029[/b:654c4848f0] in the [b:654c4848f0]Magneto Ignition Systems[/b:654c4848f0] section [i:654c4848f0][b:654c4848f0]Servicing Wico Type ?C? Magnetos[/b:654c4848f0][/i:654c4848f0] group under the [b:654c4848f0]ADJUSTING POINTS[/b:654c4848f0] paragraph on page 70-20-5.

a176722.jpg" width="650"


Hope this helps.
 
(quoted from post at 21:44:23 10/29/17) "[b:d24fa9893b][i:d24fa9893b]&lt;font color="#6699ff"&gt;It is magneto ignition. Does it have points and if so how do I adjust them.[/i:d24fa9893b][/b:d24fa9893b]&lt;/font&gt;"

Yes, the magneto has points.


Hope this helps.

Yes that helps a lot. Thanks James!
 
If the engine is in good mechanical condition, and the tractor is properly tuned as regards ignition timing, fuel mixture settings, valve lash etc., John Deere two-cylinder tractors are very smooth. Old advertising showed the tractors smoothly idling while balanced on beer bottles. My 530 and A are so smooth at idle you can hardly hear them run!
 
Your other reply mentioning "sometimes hard to start" is a good indicator it's time to look at the points! Not just the gap but their condition & how clean they are.

As far as cleanliness and gap, mags are more demanding of their points than electric distributors. Usually the hardest thing for a mag to do is to start the tractor. Once running, the shaft speed often makes up for a weak spark from dirty or mis-gapped points and it may run fine all day. Same is true of pulling. Hand crank yer guts out for only get a few pops but pull it 3 feet & it may run acceptably all day. When they're bad enough to cause irregular spark or misfire, the plugs begin to foul which then aggravates an already bad situation.

Visit those points first!
 
(quoted from post at 18:50:25 10/30/17) Your other reply mentioning "sometimes hard to start" is a good indicator it's time to look at the points! Not just the gap but their condition &amp; how clean they are.

As far as cleanliness and gap, mags are more demanding of their points than electric distributors. Usually the hardest thing for a mag to do is to start the tractor. Once running, the shaft speed often makes up for a weak spark from dirty or mis-gapped points and it may run fine all day. Same is true of pulling. Hand crank yer guts out for only get a few pops but pull it 3 feet &amp; it may run acceptably all day. When they're bad enough to cause irregular spark or misfire, the plugs begin to foul which then aggravates an already bad situation.

Visit those points first!

Got the points cleaned, they were bad, now it somewhat runs, still misses more than what it should I feel. It'll probably need a tune up kit with a rotor I'm guessing. Also, it sounds like it's running on both cylinders, but when I pull one wire it keeps running, if I pull the other it dies. What does this mean?
 
If you are pulling a plug and it dies then you are only getting one cylinder firing. This could be from one or all: bad plugs, weak spark and carb issues. Now did you have an issue at wide open throttle and Idle or just WOT? If not you may have just a clogged idle circuit in the carb. If you still have a dead cylinder in all rpm ranges you have a plug or mag issue. Stay with it. You are in the part of a tractor relationship I like the best.
 
(quoted from post at 19:59:48 10/30/17) If you are pulling a plug and it dies then you are only getting one cylinder firing. This could be from one or all: bad plugs, weak spark and carb issues. Now did you have an issue at wide open throttle and Idle or just WOT? If not you may have just a clogged idle circuit in the carb. If you still have a dead cylinder in all rpm ranges you have a plug or mag issue. Stay with it. You are in the part of a tractor relationship I like the best.

Well I decided to pull the mag and have a look see. Opened it up and years of leaves an maybe a bug or two came out. I'll attach a picture of the lag timing I believe it's called and if someone could tell me if it's in the correct spot. It's got a really strong "kick" when you turn it so that seems ok. Also if someone could tell me if it's a 25 or 35 degree mag. Here's the numbers: 1042 and then h331177
5415.jpg
 

Also I noticed that cup thing Is broke. Will that effect anything? How do I take that off to clean it? I also noticed if you soon the mag just a tad fast the paws don't come out in time to trip. Does something need adjusted?
 
Also, when testing the capacitor, I get nothing. (See pic to make sure I have it on the right setting)
5416.jpg
 
I would get yourself a new condenser and
points. They come in a kit...they sell them
at your local dealer or sometimes
thiesens/tractor supply. Also change the
plugs. I wouldn't worry about the drive
coupler or the impulse. It is designed to
disengage at higher speed. I would start
with the simple stuff then the more in depth
stuff if simple doesn't work.
 
"[b:654c4848f0][i:654c4848f0]<font color="#6699ff">when I pull one wire it keeps running, if I pull the other it dies. What does this mean?[/i:654c4848f0][/b:654c4848f0]</font>"

The spark plug wire could be broken or "shorting out".

You might consider using an in-line ignition spark tester.

a176804.jpg" width="650"


a176807.jpg" width="650"


Connect the in-line ignition spark tester between the spark plug wire and the spark plug.

Turn the ignition on and crank the engine.

If the light flashes, then replace the spark plug.

If the light does not flash, then replace the spark plug wire.

In addition, you might also clean the tip of the spring inside the distributor cap.

Also clean the two metal ends on the distributor arm (rotor cap).

Hope this helps.
 
"[b:654c4848f0][i:654c4848f0]<font color="#6699ff">I'll attach a picture of the lag timing I believe it's called and if someone could tell me if it's in the correct spot.[/i:654c4848f0][/b:654c4848f0]</font>"

Take a look at the information and illustration below.

a176808.jpg" width="650"


a176809.jpg" width="650"


Hope this helps.
 
Does anyone know where I can get a cap for a type c wico mag? I want to replace it because I'm not getting very good spark from on side and it's really worn. Everywhere I've looked is our of stock
 
http://www.bransonenterprises.com/product_info.php?cPath=58_343&products_id=434 $45 plus shipping from IL
 
Alright so new points, condenser, rotor and adjusted the lag timing and the b starts a lot easier and runs better. Still not amazing though. It almost sounds like it has a knock on the right cylinder but it's very inconsistent so I wonder if it's just a timing thing or something simple. Also, I switched the plugs and tried starting, wouldn't start and pulled both plugs, one was dry and one was dry. Switches them and started right up. Both wires get good spark. Spark plugs bad? Also it only runs rich too.
 
Ok so had the b out running around for a bit. Seemed to start running better. But then ran out of gas. Filled up. And wouldn't start. Had to pull it and finally started but pretty rough. Got it back home thankfully. Could this be stuff in the tank? Carb rebuild? Also, when I put it in 6th and put in the clutch, it stumbles quite a bit before it winds up.
 

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