Allis Chalmers B

Ben Riddle

New User
About a year ago my grandfather passed away and recently I have been working on his antique tractors trying to get them all running right. I have been working on an allis chalmers B for about 2 weeks. I have got the starter rebuilt cleaned the fuel system got a new battery and changed the plugs and it still wont crank. One of my concerns was maybe that I had something hooked up wrong with the battery, from what I know im pretty sure that it is supposed to be 6 volt pos ground.It has been fully restored so I was thinking that it could have possibly been switched? How do I check that? When I hook it up positive ground after a few times of trying to crank it the neg cable will start smoking. what would happen if I tried it the other way?
Thanks guys hope to get some feedback.
 
When you mean that it "won't crank" do you mean the engine will not roll the crankshaft, and does the crankshaft rotate when you use a hand crank?
 
Will the engine turn by hand with the crank, or by prying on the starter ring gear, or by jacking up one rear wheel, put it in third gear and rocking the wheel? If not, you will need to determine why the engine is stuck and go from there.
good luck and keep us posted on your progess.
Dennis
 
Yes the motor is free And it will turn over I just can"t get it to start in better terms. I had a buddy tell me to take a spark plug out and connect it to the plug wire then put the plug up next to the block and turn it over to see if it has fire. I did that and it will spark so I"m guessing the magneto is okay? It"s just frustrating because my grandfather could have told me what to do and now he is no longer here. I appreciate everybody"s advice on here thank you.
 
Sure the starter motor is 6v? Also, does the starter motor spin at all? If the cables smoke, there is an awful high current draw to the starter and that is where your problem is
 
Check the timing! The instant you have spark at number plug (closest to radiator) on the compression stroke you need to have TDC in the inspection hole on the left side looking from the seat.
 
does it have a generator or an alternator? If it has an alternator it is set up for 12 volts. What gauge wire goes to the starter? If it is a small gauge, like on a 12 volt auto, it is too thin. That is why it heats up. You need #1 or #0 wire for 6 volts.
If it doesn't spin over how did you get a spark. If it spins and doesn't start and you have spark, pull the plug and squirt some gas into each cylinder, reinstall to plugs and see if it will start. LOL Bob
 
Ben,
If fuel and spark are in working order those engines will generally start on 1st or 2nd revolution.
As far as the cable getting hot, is caused by too much load or too small of cable or maybe the cable is bad internally.
Like chalmersbob said, if alternator would be 12V negative ground, if generator probably 6V positive ground.
How long has it been since it last ran?
good luck with it
Dennis
 
UPDATE: today I went and bought a new cable to run from the starter to the battery because the other one was fried. That made it turn over a lot faster which I was happy to see and the cable doesn't heat up anymore. Now it is able to pull gas to the plugs which I was also happy to see but I have ran into another problem. It now seems to have lost fire to the plugs. Any suggestions? Thanks guys
 
take all four plugs out put about 2 oz. motor oil in each hole, replace plugs and wires, if it is firing and getting gas it will crank, or at least pop, sounds like you don"t have enough compression, the oil fill fix that long enough to get it cranked.
 
Two things to check first. The very first thing is to make sure the pull switch is in the correct position. I have one that you pull the switch out to start and another that I have to push it in to start. They both look alike. If you don't know how to check the switch just remove the wire on the side of the magneto. The switch to a magneto just shorts it out to the frame.
The other first would be to clean the points. Many times the points have a film form that keep them from making a spark.

Those can be done without removing the magneto.
 
Dick L , this tractor has a key switch so could there still be a problem there? An where are the points located and how do you get to them without removing the magneto? Thanks
 
Can anyone tell me how to clean the points on the magneto and what they look like? I'm having a very rough time with this thanks guys
 
points are on the cap , take cap off look at the points inside the cap (really only think in there see it the straight sguare edge, and cust use ur fingernail to see if there anything on them
 
Ben, in what part of the country are you located, if you don't mind me asking. I am in Piedmont area of North Carolina. I might can help if you happen to be close by. Was Norman Riddle your grandfather?

Garry F.
 
Two screws on the cap. Remove cap. Tape the rotor so it will not turn. Remover four corner screws and remove cover. The points are in right there. If the rotor turns the teeth will not mesh correctly when replacing the cover and you will have to retime the magneto.

If you have a magneto and not a distributor and a key switch, it still only shorts out the points so you do not have a spark. A magneto makes its own voltage unlike a distributor that needs voltage from a battery.
 
MagnetoDrawing-vi.jpg
 
Ben,

Norman grew up 1/2 mile from us, and me & my dad have bought 3 or 4 Allis tractors from him over the years. He was a great and interesting fellow. As for getting the B or others going, call me ANYTIME, 336-399-eight seven five three & I will bring tools etc. up there & we will get them squared away. I am one county over, in Davie, as you know, just off Redland Rd. I am not working my main job right now, so have some time to help and will be happy to assist!

Garry Foster
 
That's great Garry!! I will give you a call one day soon and we
can set up a time for you to come by. I greatly appreciate your
intrest in helping me out.
 

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