B still won't start

[Bill Carr]

Still baffled. Farmall B starts for a second, and quits, as if fuel or spark quits. Gas supply is good at carb, and the carb has been cleaned. Magneto has a good impulse click.

I tried Pull starting, without results. The result was the same. Only an initial start as with the crank. The firing seemed sustained slightly longer when popping the clutch in 4th gear than in 3rd. But essentially no better than when crank starting, which is sometimes slightly more sustained too. (But still never more than a second)

 

[El Toro]

Have you held your hand over the throat of the carburetor to see if there's good suction? Set the valves at .017" cold. Do a compression check on the engine and post the readings. Have you looked for fire to the sparkplugs? Post a picture of the mag and plug wires. When you bring No1 piston near the radiator to TDC on the compression stroke have you checked to see if both valves on No1 cylinder are closed? See if
your timing marks are aligned on the flywheel and if the rotor in the mag is pointing to No1 plug wire. Hal

 

[Mike Farmer]

My first thought on this one is condenser. MTF

 

[Oldiron29]

Bill, I am with Hal I would look to the spark coils can do funny things spark sometime and than no spark others. oldiron29

 

[Janicholson]

This seems like a wierd idea, but it will pinpoint the issue.
Go to Radio Shack and buy a a single Ne2 neon bulb (very cheap). Find a piece of rubber hose that it will push into and cut a 4" piece.
Take some stranded insulated #14 wire about 4'long, and solder on connections to the bulb. Use tape or shrink tubing to make sure it does not short out at the leads.
Push the bulb into the hose and squirt silicon caulk, or blue RTV gasket goo down the other end to hold all in place. Attach an alligator clip to one lead, and solder it. Attach 2' of #24 enameled wire to the other lead. Let dry.
To use this device, wrap the enameled wire around the high voltage wire going from the mag coil to the center tower of the cap. Use the length of the wire to make many turns (at least 15).
ground the other lead to a frame clean ground.
At dusk, or in dim light, start the tractor while looking at the bulb. It will light up on every firing impulse in the spark wire. If it does, then does not, It is the mag. If it stays operating then the mag portion is probably OK.
The Rotor and gear might be off a tooth inside the mag, allowing the rotor to miss the tower terminal when it starts. Try it on one of the plug wires to see if it continues to spark there. If it does not, I suspect the rotor timing gear is off a tooth. This can also be done with an inductive timing light, but this works. JimN

 

[teddy52food]

If you have anyone in that area that works on magnetos, take it off and have it checked out. Maybe send it to magman. How far away are you? I work on them also in central Mn.