My F1 never likes to start after setting for a few days. I always have to crank it a very long time while pumping the throttle. If I give it a shot of gas in the carb, it starts instantly. It seems the the gas in the carb is going somewhere while it sets. The truck does not have to be hot for this to happen so it's not boiling out. Any suggestions on how to fix this problem. I've already rebuilt the carb and fuel pump.
Dan

 

Did you check the float adjustment, this is critical, check the measurement with the float height on top (gravity holding it closed) and then let it hang upside down (open)and check this measurement.

Sounds like it is not getting enough gas, screws in back of this carb turn out for more gas.

If all else fails you could have an air leak either in the carb, under the carb, vaccuum line or the intake which would cause the engine to need additional gas. You can check for leaks by putting oil on the suspected area, it will smooth out for a while until the oil gets sucked in and burns blue.

 

It sounds like your accelerator pump is shot and it isn't primering your cylinders, you can check this by opening the butter fly on the carb and pump the throttle a few times and see if any fuel is squirting in the carb.

 

Is your choke hooked up? Mine has a slight gasket leak and acts the same when cold. Until I get around to changing the carb gaskets and rebuilding, it's pretty easy to pull the choke on part-way. Engine fires right off when cold. - Tim

 

If the carb/intake check out OK put a plastic viewable filter between pump and carb. This will tell you if the gas is draining back into the tank or even possibly into the oil.

Also look for air bubbles in the filter. If there you have a leak at a fitting, very thin /perforated line or tank.

I had a similar problem and installed a plastic fuel shut-off between carb and pump until I got around to redoing the lines. A few bucks at a small engine shop.

 

Thanks to all who provided suggestions. Here's what I found: My brand new fuel line had completely plugged with varnish and rust from the tank. I removed the line and couldn't even blow 100 psi air through it, let alone 5 psi fuel. I soaked the line with carb cleaner for several days and finally got it open. While I was at it, I removed the tank and cleaned and sealed it. I did it myself to save a few bucks. I wouldn't have believed that there could be so much crud in the tank. It cleaned up nicely and I sealed it with POR-15's brand of tank sealer. So far so good. The last thing that I found was that the point gap was at .025" instead of .015". That made a big difference (more dwell means hotter spark). Now it starts and idles like a dream. I'm having fun driving it all over the place. I still can't bring myself to prime over the rust. I really like the "just dragged from the barn" look.