51 B I am at a loss, please help

So my 51 Deere B was running pretty darn good about 3 weeks. I ordered a carb gasket kit to repair some worn gaskets, and I also ordered a new throttle handle as mine was broken. Took the pedestal off to repair the throttle handle, took the carb off to put the new gasket kit on. I also cleaned up some wiring related to the headlights, someone had wired in a secondary switch that I wanted to get rid of.

Ever since, I can't get the tractor to start. Now I know the carb is clean, I've been through it several times. To confirm that fuel is not the problem, i shot starting fluid into both cylinders then tried to start it and nothing. A small cough at best. Must be electrical?

I checked for spark at the plugs and it looked okay. I took a section of wire and ran it from the mag to a section bare metal. It would jump a good 3/16 to 1/4 inch gap. Seems to me mag is okay. I also tried to pull start it (maybe mag impulse is bad) and got nothing. Plugs and wires are the same from when it ran 3 weeks ago. I took off magneto and retimed it anout 2 months ago, it ran well after. Timing shouldn't have changed? I have tried a new condenser, did not help. I compression tested it and cylinders are good. Took valve cover off and all valves are moving.


What am I missing? I am unbelievably frustrated at this point.

Magneto is WICO C. Also replaced mag cover, rotor, points and condenser on that. Confirmed points are set to .015"

You have gas in it? Float stuck? Just making sure....ask me how I know!

Yes I can confirm I have gas and float is not stuck. Good idea to start with the simple stuff though!

If it's been near ten years or so you should just change out your spark plug wires for new, copper conductor ones. They will leak away that visible spark that while testing looks good enough when the plug is under compression in the engine. Drove me nuts before I gave it try having nothing else undone. Have never forgot that ten year replacement plan either.

When you open the bowel drain on the carburetor do you have steady flow or does it slow to a drip after a minute or so? did you happen to switch the plug wires in the mag when you were working on it?

I have a good stream for about 30 seconds, I have never tested it for longer but will try. Yes I can confirm wires are going to correct cylinders from mag, top hole on mag to flywheel/starter LH side.

I just ordered a set to try. It can't hurt at this point, and the ones on I have no idea how old they are. Did this cause your tractor to not start?

Late styled B's equipped with mags shut down by pulling the throttle lever all the way back. Do you have the throttle advanced a little when you crank it?

Try a new set of spark plugs, Ac 87 or Auto-light, The number escapes me at the moment . Anything but CHAMPIONS .

Yes, I have tried various throttle/choke positions to no avail.

I currently am using a set of auto lite 3116 plugs that I bought new 3 months ago

Absolutely yes, perfect the year before and junk iron the next. I went through all the usual suspects just like you and at my wits end. Changed the wires and I had my old tractor back. Never forgot that frustration or the hard to come by easy fix.

My '51 B is an electric 6v start. It is very sensitive to throttle settings when being started. Since you fixed the throttle handle, I would check where the butterfly is when you try to start it. On my B, the throttle needs to be open just a bit..... just off slow idle but NO MORE. Anything more and it will never start. I choke it initially for a few spins then open the choke. Anything more and it floods. If it does flood, open the throttle completely and spin it for a few moments to clear the cylinders. Then go back to positioning the throttle with the butterfly maybe 1/8" off it's stop.
You didn't mention if it's an electric start or not.
Before rebuilding my generator and regulator, I used a 12v battery which made it much easier to start. But with everything set right, the 6v system usually makes it fire right up.

This is an electric start with 12V system. I will check to make sure that the throttle is where it needs to be. What gets adjusted to make this correct? You measure the gap from the little lever to the stop spring? I won't be able to see the butterfly when it is mounted.

Just saying change the sparkplugs . Doesn't hurt to have an extra set anyhow.

Are you writing from experience or from something you read or heard? I have never had a problem with Champion spark plugs. If they are so bad how does Champion stay in business?

Yes, 1/8" off the stop spring. At least on mine, that's where it likes to be. Fully closed, it won't start. Anything more than just cracked open, and the governor pulls it fully open when the motor spins. I can't guarantee that it is set up correctly, only that it works. Adjustments are located where the throttle rod from the throttle arm connect to the governor, if I recall correctly.

You may need to charge the magnet in the mag type Cs are not a permanent magnet your tractor came with Wico xh mag it is permanent magent