Weber carbs overflowing!

[tommy911]

I could not believe my eyes!! I turned on the key and like always the fuel pump comes on and I listened for the floats to come up when all the sudden gas started overflowing from the vertical air tube or what ever it is. The vertical tube is metal about 2.5 inches long and there are two on each triple bank carb (40 IDA 3C). To my knowledge they are air valves that let in air. These two vert. tubes sit on the top of the carbs and have never overflowed with gas. In order from the furthest Velocity stack it goes: Carb 6 - Vert Air tube - Carb 5- Vert. air tube- Carb 4. Something must be clogged in the carb to have gas forced out the top like this. After turning off ignition I waited a few minutes and tried it again. Same thing happened. about ten minutes later I cycled the throttle and the sound of gas flushed down into the cylinder. What do I do? Anyone have a set of Weber IDA 40 3C that this has happened to?

***Two years ago I took carbs off and cleaned them and built them back up with new stuff and car ran good up until now. I start the car up about ever 2 months and drive it around. really is a great running car. Any Weber guys in the forum know what this might be? Any tips on where to go and read up about this? Thanks!

Thanks !!!!

-Tommy911

[1QuickS]

Were both vent pipes over-flowing? I'd bet that only one was. The float stuck and allowed the gas to keep filling so you probably want to investigate the issue. Remove spark plugs and turn off ignition to crank the engine through to clear the gas out of the cylinder. Many small items can cause flooding such as: crud under the needle seat from dirty fuel supply; when the fuel in the well evaporates the float drops and when fuel is supplied again the needle sweeps along a tab on the float which could be less than smooth (divoted from wear or corroded from inactivity) and cause a binding to occur; fuel pressure should be set to 3.5 psi and a good quality fuel pressure regulator used for this purpose; fuel has gone to goo as a result of old fuel not being cycled out by driving the car enough (drive it or use fuel stabilizer preferably both.)

Check out my web page regarding Weber technical info: http://www.performanceoriented.com/technical.htm#FuelFloat

Hope this helps.

[Joe Bob]

Fuel pressure or stuck floats.....

[haycait911]

mine did this. stuck floats. tap the carb with a wrench.

[Tim K]

Think about changing your oil too. I hope it's just a stuck float.

Welcome to the forum.

Tim K