Got half way around the block and it was running great (comparitively) then it stalled in the worst place and won't stay started.

 

I'd like to correct my earlier suggestion that it was the worst place. 10 minutes after I posted that I met a neighbor I had not met before (I was in front of his house) Turns out he is a mechanic and knows a little about flatheads (he can't know less than me). He took one listen and said "sounds like it is starving for fuel" Checked the pump and sure enough it was coming out at a trickle. Enough to run the truck at idle evidently but not enough to drive. I will check in the morning to see if it flows more when cool. In any event it will need a new pump.

 

It could be the pump, or it could be a plugged line.

 

I was just thinking about same thing but I am not sure how to diagnose the clogged line without taking the tank out. It looks as though someone has already had the tank cleaned but without taking it out its tough to tell. I am going to see how much the pump puts out in the morning and it if is still low I'll disconnect the hose and see how fast it flows with gravity.

 

Blowing through the hose into the tank might get a clogged line free enough to drive a short ways. Make sure the filler cap is vented too.

 

I hate being stuck! On the bright side you met your neighbors and a mechanic....bonus.

Simplest thing to do is as The Horvaths suggested....blow back through the fuel line from the fuel pump to the tank to see if there is any obstruction.
You might also check and rubber line between the fuel pump and the fuel tank. If the rubber lines are old, dehydrated, and brittle there is a chance that they are sucking air instead of fuel.

Good luck
Bobby

 

I had the same problem with my truck. 60 years of sludge, rust and other misc crap have accumulated in the bottom of the tank and the gas drains directly off the bottom of the tank. I took the tank out and flushed it out with water. When I installed the fitting on the bottom of the tank I put a small length of copper tubing in the fitting, just enough to raise the level of where th fuel draws off(about 1'') and tied a piece of copper screen on it to act as a filter.......that cured that problem

 

All good suggestions. One other I was thinking of was the fuel pump location. The previous owner mounted the external fuel pump on the fire wall at about the same height as the carburetor. It is on the drivers side above the exhaust ( a couple feet above). It is certainly easier to access the filter and pump but it is a pretty good distance above the bottom of the tank as Holley pumps suggest they should be mounted (Mine is not a Holley but I was looking for general mounting guidelines). I am curious where other have their's located?

Is the possible solution to prime the pump and then never run it out of gas? Or should I consider moving the pump? It seems like a difficult challenge to mount it lower than the tank but not where it can be damaged by road debris and away from significant heat sources.

 

I'm moving my electric pump from inner fender to frame area just to mitigate priming issues. It doesn't absolutely need to be below the tank, just put it as low as you can and still safely secure it.

 

The original fuel pump was designed to pull fuel by creating a vacuum where the electric pumps are designed to push fuel. There are some pulse type electric pumps that will 'suck' fuel but I've not seen one of them in years. If it were mine, I would lower the pump and get it away from exhaust heat.

 

Wow I see now why the pump is where it is. Everywhere I see from the tank to the carb that is usable is right above exhaust. Maybe I can put it on the inner fender. and use a heat shield. Maybe on the outside of the frame rail...

 

Same thing that I did after I knocked as much rust out as I was able and soldered up a few small holes in the bottom . Maybe I will pick up a new tank the next time I go out to Vancouver

 

As Ray says, electric fuel pumps are pushers, not pullers. Remount the pump as close to the tank as you can, plumb it with steel tubing from the tank to the pump, from the pump along the inside of the frame to the front of the motor, add a filter (I prefer clear inline filter since you can see the fuel flow). Use teflon lined SS braid flex line from the steel line to the carb. The new fuel mixes E- 10+ eats solid rubber line from the inside out. If you must use rubber fuel tubing keep it as short as possible, 6" or less, replace it once a year.

 

Mine is mounted about halfway along the door, inside the frame rail. I am using new custom-bent fuel line. Plenty of clearance to exhaust.

 

I was thinking about the gusset opposite the brake matter cylinder.

On a related note I opened up the fuel tank to verify what the previous owner told me about having cleaned the Tank. Could not be much rustier. Looks like I need to look into tank cleaning.