I just finished rebuilding and installing the 1 bbl carb on my 1981 F100, I6. It was leaking fuel out of the bowl somehow and into the intake and wouldn't start after sitting (not running) for awhile without priming. Raw gas in the intake manifold caused a lot of smoke as you can imagine.
The rebuild went fine and now there is no smoke and it runs fine. I am waiting now to give it a chance (if its going to) to leak from the bowl while sitting and not running. I will inform of success or failure. Wish me luck because this is my first rebuild endeavor.

Gene Johnson

 

Well, it is still acting the same. I let it sit for a few hours and it wouldn't start without pouring some gas into the carb. After that it ran and started O.K., but leave it turned off for any length of time and it won't start.
The rebuild was done very carefully and to all specs indicated. When the engine is running it seems the gas is trickling very slow (see thru filter) from the mechanical pump. The inlet to the bowl appears to have a check valve in it, but even if it was bad, I don't think the gas could flow up and out of the bowl and out the line back towards the pump. In any case the bowl should still hold enough to start the engine! I'm at my wits end. Does anyone have any ideas. How could the gas escape from the bowl?

Gene Johnson

 

When you did the rebuild did you replace the needle and seat, and adjust the float right? Could the filter be clogged? Have you tried turning the engine over with the gas line disconnected to see if the pump is working? Try not to smoke when you do this, and try to catch the gas in a coffee can or something. Is the choke working? All I can do is guess without seeing it. Good luck.

 

Thanks trike1946, I changed the needle and seat, the float was set to spec. I was very careful with the rebuild. I was thinking that the pump wasn't putting out enough to fill the bowl but after you prime start it, It will start over and over again until you leave it for awhile. SOOOO the filter is not clogged either. Its not throwing out black smoke out on startup like it was before the rebuild so i feel the gas is not leaking into the intake. All I see that bothers me is a weak out put from the pump. I cant see where that would take fuel from the bowl????

Gene Johnson

 

Gene, if were me I would eliminate the pump part of the problem and replace it and the filter. If that does not change things, I would take another look in the carb, and if nothing looks bad, I would go to a bone yard and get another one and put the good parts in it. I never had the problem you are experiencing so I am just guessing. Wish I could be more help.