I was working on a stuck float on my wife’s ‘79 F150 yesterday.
The truck has a 470 Truck Avenger on the 300 straight 6, designed for off road applications.
This crossed my little brain yesterday while adjusting the fuel bowl levels.

How often does the secondary fuel bowl get fresh fuel?
It’s primarily run on the streets and to camp…no hardcore four wheeling and rock climbing.
Of course she drives it like a formula one car at times.

This carb is designed with a built in “sprinkler system”…a tube with holes connecting both vents.
The “sprinkler system” went off last week at idle and sitting on level garage floor after getting to operating temperature.  I had the air cleaner off at the time and knew the cause.  This happened a couple of years ago…so bad that the engine was flooded and towed home due to a dead battery.  I was able to figure out the issue at home.

I clamped off the rubber inlet line to allow fuel level to drop and then released it to fill the bowls again.
Problem solved as far as diagnostic testing. Plan is to go through fuel system and most likely rebuild the carb this summer.  Both floats were already set on the low side…no fuel at sight plugs.

I figure the rubber fuel lines, regulator (set to 5 psi), steel hard lines and gas tank have crud in them causing the problem.

BTW, this truck still runs a Duraspark ignition system.

Last edited by Nos681 (5/12/2023 12:14 PM)