I HAVE HAD A PROBLEM IN THE PAST WITH A PIECE OF FINE RUST GETTING IN THE NEEDLE SHUT OFF OF THE VACCUM TANK AND NOT SHUTTING OFF THE GAS,AND THE GAS POURING OUT THE OVER FLOW ONTO THE EXHAUST LUCKY NO FIRE. IF I PUT A GLASS BOWL FILTER ON THE INLET SIDE OF THE TANK WOULD IT STILL PULL THE GAS OR RESTICT IT.

The needle valve is at the top of of the tank. If the valve does not shut the gas gets sucked into the intake manifold. Then the engine burns it with a lot of black smoke. By filtering the gas should have no effect on the needle valve since it only sees air at the top. I had a similar problem except my float had a pin hole and with the weight of gas it did not have enough force to close the valve. When the float goes up there are springs on the valve that usually slam it shut. The only solution is replace or fix the needle valve to stop the vacuum.

MY TANK HAS A OVER FLOW TUBE ON THE TOP WHICH ALLOWS THE GAS TO ESCAPE OUT OF THE TANK BEFORE THE VACCUM LEVEL SO THE GAS DOESN'T MAKE ITS WAY TO THE VACCUM LINE. ALSO IT WOULDN'T TAKE MUCH FOR THIS FLOAT TO GET HUNG UP THAT'S WHY I WAS THINKING OF MOVING THE GLASS BOWL FILTER FROM THE CARB. SIDE OF THE TANK TO THE INLET SIDE.

I put a sub micron filter on my fuel line and solved the problem. You MUST use a low pressure drop filter, since you have only the vacuume. I used a Dahl filter. It is a cast bowl, and allows the vacuum tank to pull the fuel without problem. I empty the bosleach fall, and get a small amount of rust/dirt each time. Have not had a problem since I put this in.

mikzjr....I think you are refering to the atmospheric vent. If the float sinks it will suck the gas into the engine. Ceck your atmospheric vent for stoppage.

Patrick do you have a number of the one you used and where did you get it. If it worked for you lets stay with it. Also where did you mount it. mike