My WD will start fine, run for 1 - 2 minutes and then die.  It will restart but then die in a shorter amount of time.  It sounds like it's not getting fuel - or it runs the fuel out of the carb bowl and then dies.  The longer it sets between starts the longer it runs before stopping.  

This happened several years ago and it the problem was debris in my gas tank.

I cleaned out the gas tank, replaced the sediment bowl asy (I warped the old one when I overtightened the nut holding on the bowl), blew out the fuel line, and 'rebuilt' the carburetor.  The carburetor rebuild consisted of replacing the idle and running valves/seats, blowing out all other passages, dipping everything in carb cleaner for 3 days, and re-assemblying with new gaskets.  I did not replace the floats.  I have done minor adjustments to the needle valves and that improved how it ran/idled but didn't prevent the engine from stopping.

The floats appeared to be leak free and they were 'loose' when I shook the carb before installing.

I'm leaning toward taking the carb apart again and checking floats and the float 'valve'.

Any suggestions?  I need to get some snow moved.  Any help is appreciated.

I think you're on the right track. Sounds to me like its a fuel delivery problem. Very slow fuel delivery. When it sits, for a short while the fuel bowl fills up with enough fuel to get it to run for a short period of time and then dies. I'm wit' Mike on this one. Remove the sediment bowl. You might have some debris blocking the exit hole to the bowl. If the floats where sinking, the Carburetor would be spewing fuel out the intake hose and running down. I've also seen on the WD45's, if the Distributor mainshaft bushing is worn enough to make the mainshaft wobble, it loses the dwell and shuts down. Easy way to tell if that is the problem is to pop the cap off, grab a hold of the rotor and see if you can move it side to side .0002-.0003"  If so, it might possibly be your problem if its lose. If there's no side to side then rule out the Distributor. You could also do a condenser change as well. When was the last time it was tuned up? Just might need a set of points and condenser..... Couple things there to check out.

Steve@B&B

I'll go after the gas tank and sediment bowl again.  Something may have stirred up.

Sounds like the consensus is that it's not likely to be an internal carb problem.

I appreciate everyone's input.  Thanks!

Certainly sounds like the tank vent cap isn't venting, or something similar... but  What I would do is troubleshoot.

First of all, you noted the nature of "Once it stalls, the longer it sets, the longer it runs"... The tank vent and fuel flow would certainly be high on my suspicion, but this SCREAMS to me "Thermodynamics"... something is either hot, or cold.

Start it up, let it get warmed up, and running... and when it gets to the point where it starts to stall, put a little shot of something flammable into the intake and see if it jumps back into line.  If it does, you have a fuel problem.

If not, it's either ignition, or ice in the intake manifold...

After it stalls, put the back of your hand against the ignition coil... is it hot?  If so, you either have excessive dwell, or an ignition coil with a shorted primary winding.

If the ignition coil isn't hot, try connecting a jumper wire from the battery, direct to the coil, and see if it settles down.  If so, you have an ignition switch contact or wire that has corrosion on it, and it's heating up and failing to conduct.

Is the area above the carbeurator getting frosty?  If so...

Manifold ice... occurs when ambient airflow coming through the carbeurator venturi is rapidly chilled in the divergent zone (just about where the throttle plate is).  This happens naturally in ANY throttled-engine, or any restriction point.  Moisture in the air will freeze to the inside of the intake, and close off the intake airflow, oftentimes it'll cause the throttle plate to get stuck.  Properly designed engines have features to help prevent this, but it's a natural phenomena of physics... and the visible giveaway is frost on the OUTSIDE of the intake manifold.  The Allis intake and exhaust manifold shares a common surface just above the throttle to alleviate carb/manifold ice, but that doesn't stop it from happening, especially on a humid and cool day.

And if you did a thorough restoration, you've got the oil-bath air cleaner on... Have you tried disconnecting it?  If not... try that, and if it doesn't stall, the air cleaner needs an exam... sometimes they wind up with water beneath the oil and it causes havoc.

Gentlemen,  Please remember we are talking an OLD OPERATING TRACTOR - around 75 years.  Remarkable that it is still operating so well - they made them good then. When considering what makes them not run efficiently we have to look at all angles even one we don't think is possible because of the age. 

If you still have a magneto how about the coil or maybe a condenser.  If it has been running all this time with a mag it may be time for a new coil or condenser

Let us know how it goes.

Good Luck!

Bill Long