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.

[MikeK]

help me out here.... you say the phenolic spacers will keep the heat out of the carbs.

I don't see how that fixes my issue. I parked the Bus at 8pm. At 8am I smelled gas, see gas in the barrels.... How does heat or lack of heat in a 45*F garage cause fuel from a full tank to over fill the float bowls.

What I do see.... I pulled the top of the carb, put the hose in a cup on top of the engine. I still get 1 drip per second into the cup. That makes me think the FULL line in the tank is above the end of the hose.

So I have gone back to setting the float. I have cleaned everything on the top plate, checked for debris in the float valve. Cleaned the inlet filter and now looking at the float setting.

Current settings are 11.2mm closed and 23.3mm open. Measurement are with no gasket.

I see 10mm and 32mm respectively on weber sites and other books.

You mentioned that you parked the Bus after a drive. Heat soak from the heads to the carbs can vaporize the fuel in the bowls of the carbs and in some instances may push some fuel past the needle and into your engine. This seems to be more of a problem with ethanol-mix fuels. This may or may not be your problem.

From what you describe here, it appears that your needle and seat are leaking. Viton, standard, whatever, replace them with genuine Weber parts and your problems are likely solved. If not, then it's something else.

Oh, and your fuel pressure is set too low if it's at 2 psi.

Good luck!