Weber 40 IDF is dripping Options

[malcolm2]

Nice day for a drive yesterday.... Drove some, filled up with gas and drove a bit more.



Woke up this morning to smell gas in the garage and noticed a pool of fuel on the floor.

I removed the air filter and see a drip in one barrel. 1 barrel is very wet and even has a pool sitting on one side of the plate. The others are wet, so they could be dripping, but less frequent. You know gas, it will evaporate pretty quick.

looks to be coming from the center of #14, Aux Venturi. I removed the Main Jet on that barrel (47 - 50), hoping to get it to stop dripping. I think it stopped.

What is causing this? (IMG:style_emoticons/default/WTF.gif)

I should add that Dual Carbs are new, set up at AC.net... now out of business. Last summer I fully adjusted, and sync'd them. Had been running really well, parked for about a month. Total of about 800 miles on the whole rebuild.

[malcolm2]

Had a similar thought. Run the hose, at least some of it, higher than the tank. Would be easy to try.

If I remember correctly, the pump will push the fuel. It does not do well pulling it from the tank. My old cabriolet MK1 had a pump in the tank and one under the tank.

Regardless, the damn viton tipped float valve should hold back fuel, right? Very low pressure if the pump is off, I would think.

They used L-jet FI in 73. Guess i need to study up on where those were and where the hose ran.

[Superhawk996]

Regardless, the damn viton tipped float valve should hold back fuel, right? Very low pressure if the pump is off, I would think.

I don’t think I’d agree.

When the gas tank is higher than a carb and can be gravity fed, it usually has a fuel shutoff valve. This is true with my 1948 Case tractor, lawnmowers, generators, etc.

However in all my experiences with hydraulics, it is always assumed an orifice will bleed down over time. This is true of hydraulics spool valves, solenoid valves,etc. Though they may leak down very slowly, they all leak down to some degree. This is also true of solenoid valves in ABS/ESC modules - the solenoid valves all have a degree of leakage over time if you attempt to use them as a long term line lock.

You could try adjusting float level to provide more sealing force but that may cause other issues (low fuel level in bowl) when running.

Picture I found of a bus and fuel pump