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Posted by: Downerman Apr 25 2009, 01:49 PM

Just got the new dual weber kit (40 IDF) and it's all in. Presure regulator, fuel pump, it's all in (have not started it yet) but I have a problem. One of the ports is loading up with fuel. I pulled the top and the float was working (the other port was not emitting fuel after the float reached the top. Took drivers side carb off. Setup on the trunk lid with lot's of towels and turned the key on. Like I said all the other three ports stop however this one keeps dripping fuel. I am lost and not knowing exactly what these screws do (other than the idle) I really am scared to start turning them. Why would one port emmit fuel and not the other when they share the float?

Any suggestions guys?

Posted by: 904svo Apr 25 2009, 02:53 PM

If there the new US made 40's sent it back for replacement.

Posted by: Downerman Apr 25 2009, 04:10 PM

They are..... the fuel is comming out of four tiny holes about 1/3 up the cylinder port (From the bottom). Fuel just drips out even with no pressure (just fuel in the bowl).

Not real impressed with this kit I bought. I hope they run good.

Posted by: 904svo Apr 25 2009, 05:29 PM

Jake stop using the new Weber's as they had a lot of problems with QC.
He and Art work with EMPI on there version of Weber 40's to correct the
problems. One of Jake's peeves was the poor casting that are on the
carbs, they leak!

Posted by: maf914 Apr 27 2009, 11:54 AM

Check the float level measurement. I followed the Haynes Weber manual for this after one of my 40 IDF's started dribbling fuel into the carb throat after previously running fine for years.

Of course, this won't solve anything if the carb body casting is porous and leaks.

Posted by: lotus_65 Apr 27 2009, 06:19 PM

I'm have the same issue with mine, they drip exactly like you describe. I got mine from PMO, and they want me to deal with the guy who installed them back when I knew nothing.
'Course he's retired, and I don't know if I'd want him in my engine again anyway.

The consensus around here is too much fuel is better than too little, but I think my issue played a role in the premature demise of my fresh Raby 2056, so I don't exactly know. If you are running an engine that hasn't been just rebuilt, I'd say run it and see what happens. I don't think you'll endanger the motor, you'll just have a thimble or 2 of fuel washing the cylinders when you fire it up.

good luck to us, I guess... But maybe you could return the one.

Posted by: Racer Chris Apr 27 2009, 06:34 PM

Just sell the car now.

Posted by: type2man Apr 27 2009, 07:55 PM

Put it all back together and try running the car up and down the street and see how it runs. Then shut it off for 10 minutes and try to start it. If it is hard to start and blows black smoke out the tailpipe something is wrong. Maybe what you are seeing is normal???? My other guess is too much fuel pressure???? Are you installing this set of carbs to replace another set or switching over from fuel infection???

Posted by: type11969 Apr 27 2009, 08:46 PM

Check the fuel pressure, definitely check the float height. Also check to see if there is crud in the seat of the needle valve. If the float height is right, you can always tweak it a bit further to make it close sooner to see if that helps.

Posted by: lotus_65 Apr 28 2009, 03:47 AM

except I'd warm it to operating temp.

doubt it. if i get his comments correctly, he is only experiencing it in one barrel, (like mine). in troubleshooting my issue, i pulled the fuel line and capped the tips... it still seeped. i lowered the float level about 3mm lower than i was comfortable & checked for crud, but it is still dripping.
i think it's a casting issue.

Posted by: jmill Apr 28 2009, 07:02 AM

Sounds like its coming out of the progression ports. Fuel should only flow from there when you transition from the idle jets to the mains. The butterfly position determines whether or not your pulling a vacuum on the ports.

Posted by: Racer Chris Apr 28 2009, 07:05 AM

If its a casting issue there is no purpose whatsoever in atttempting to operate the engine with them installed. It will be unproductive and unsafe.
Things like that don't cure themselves. They just create much bigger problems.
Sometimes one barrel might drip fuel while the engine is running due to a loose screw or bad adjustment. But if only one barrel drips while the pump is running and the engine is stopped it will almost certainly be a damaged casting.
If you don't have the skills to diagnose such problems seek professional help for the problem immediately instead of risking engine failure or fire.

If I had a set of brand new carbs that bahaved as described I would be in contact with the seller immediately, requesting a return authorization number, and full credit or replacement. If the seller is reluctant to cooperate, take it to the next higher authority.
Uncontrolled fuel flow is dangerous!

Posted by: jmill Apr 28 2009, 07:15 AM

I also suspect a bad casting. Fuel should only flow from those ports when the engine is running and there is a vacuum on the ports (butterfly in transition from idle to mains). You are talking about the little holes just above the butterfly when it is closed? If thats where it's coming from I would return them.

Improper float adjustment will cause fuel to flow out of the mains with the engine off and the pump running.