Weber idf 44 leak!, Help! Options

[ThePaintedMan]

There are a lot of variables, not to mention good advice from others. So I think I'll shut my mouth after this so as not to add too many voices here to confuse you.

Like Jake said, it would be nice to see pics of the offending carb.

Mark makes a good point too - if fuel is bubbling up over the bowl and into the TB, then you have an issue with the float, and possibly with the gasket too. At this point you've taken them apart enough (and they're six years old) that it's probably time to go ahead and replace the gasket anyway.

What kind of linkage do you have on the carbs currently? Positive that it's synched correctly? A throttle being held slightly open can allow the accel pumps to dribble fuel (not sure if you've verified for sure that it's not actually coming from the pump jet).

[Milkman7286]

Would bad gaskets cause something like this?

Gaskets should be changed every time you crack the top. Fuel sloshing around in the float bowl could leak around a bad gasket or a warped top.

How new are these carbs? Do you have a pic of one of them, preferably from the float bowl side?

You thinking inferior casting?

So it sounds like the gaskets aren't the issue despite needing to be replaced. This happens when the car is off so no fuel pump going.

Just a quick update to all:
Last night I lowered the fuel pressure a tiny bit and also set the float height to a little lower (more like 12mm with the gasket in place now) just to see what would happen. Took it for a spin and came back. When I got back I didn't hear anything immediately but I didn't take the filter off to visibly check either. I cracked the throttle by hand however and let it close and after doing so the carb began to gurgle so apparently neither of my changes made a difference.

[Milkman7286]

Would bad gaskets cause something like this?

Gaskets should be changed every time you crack the top. Fuel sloshing around in the float bowl could leak around a bad gasket or a warped top.

How new are these carbs? Do you have a pic of one of them, preferably from the float bowl side?

You thinking inferior casting?

So it sounds like the gaskets aren't the issue despite needing to be replaced. This happens when the car is off so no fuel pump going.

Just a quick update to all:
Last night I lowered the fuel pressure a tiny bit and also set the float height to a little lower (more like 12mm with the gasket in place now) just to see what would happen. Took it for a spin and came back. When I got back I didn't hear anything immediately but I didn't take the filter off to visibly check either. I cracked the throttle by hand however and let it close and after doing so the carb began to gurgle so apparently neither of my changes made a difference.

[jmill]

Do you have thick manifold to head spacers?

Sounds like they are getting heat soaked. Heat from head transfers to carb. Boils the fuel. Carb gurgles. Bubbles form in idle circuit. Since drilled passage is small the bubbles carry fuel through the circuit and you see it weep out of the progression ports.

[Milkman7286]

Do you have thick manifold to head spacers?

Sounds like they are getting heat soaked. Heat from head transfers to carb. Boils the fuel. Carb gurgles. Bubbles form in idle circuit. Since drilled passage is small the bubbles carry fuel through the circuit and you see it weep out of the progression ports.

I considered that. I do not have the phenolic spacers so that might be part of this. Problem is the carb is leaking when the motor is cold too so I'm not too sure if these spacers are the final answer.

[jmill]

The carb bubbling and gurgling after running sounds like textbook heat soak.

Without a stuck float or bad inlet needle valve or seat, fuel "shouldn't" get as high as the top gasket. You'd also see it dump out of the aux vents. It's pretty easy to spot. It "should" only get as high as your preset float level. The idle circuit is drilled higher but requires vacuum to pull it up. The accelerator pump circuit is drilled higher but requires pump actuation.

I'm at a loss. (IMG:style_emoticons/default/confused24.gif) Need pictures with leakage area circled.

I've heard about inferior/flawed castings. I believe they're out there but I've only seen slightly mis-drilled butterfly shafts.

[brant]

did you test the floats in a cup of water when you had them apart...
any chance you could have a bad float?

[ThePaintedMan]

The carb bubbling and gurgling after running sounds like textbook heat soak.

Without a stuck float or bad inlet needle valve or seat, fuel "shouldn't" get as high as the top gasket. You'd also see it dump out of the aux vents. It's pretty easy to spot. It "should" only get as high as your preset float level. The idle circuit is drilled higher but requires vacuum to pull it up. The accelerator pump circuit is drilled higher but requires pump actuation.

I'm at a loss. (IMG:style_emoticons/default/confused24.gif) Need pictures with leakage area circled.

I've heard about inferior/flawed castings. I believe they're out there but I've only seen slightly mis-drilled butterfly shafts.

Again, I agree. At this point we can't offer much more help till you take pictures.

You told us that the car had been running and driving fine, but all of a sudden this issue arose. So there is nothing mechanically that changed to be the source of the problem. Which means something plan ol' wore out. Keep in mind that the carbs are now six years old. Even if you've set the floats correctly, the needle valves are likely brittle and could be the source of your leak, even with the engine off. The heat soak is likely exacerbating the problem. Seals, gaskets, etc in carbs have a shelf life, like everything else. Ethanol in fuel has reduced that shelf life some as well.

The fix: rebuild the carbs or at minimum install new needles and seats. You have removed the tops enough now that the gaskets are toast, as others have told you.

While the carbs are being rebuilt, consider installing the phenolic spacers between the head and the intake to get rid of the heat soak.

Edit: I like Brant's suggestion too, if nothing else for piece of mind.

[72hardtop]

Well,
It wasn't the choke pieces, the plungers weren't even there.

Would bad gaskets cause something like this?

Ding, ding, ding. The plungers need to be in place or plugged. If not that is your issue. Even if one chooses to not use the enrichment circuits they still need to be in place or plugged...one or the other. Which is it? Post a photo of the circuits.

[jmill]

Ding, ding, ding. The plungers need to be in place or plugged. If not that is your issue. Even if one chooses to not use the enrichment circuits they still need to be in place or plugged...one or the other. Which is it? Post a photo of the circuits.

They make IDFs without the enrichment circuit machined. You won't see plungers or plugs. Remove the block off plate and there's nothing behind it but bare casting.

[Al Meredith]

Are you sure they are Webers? About 6 years ago "EMPI" started importing Webers made in China. The first couple of batches were porous . I had a 914 owner come to me about a year ago and the Chinese carbs and manifolds were stained with fuel that was not comming from any place where there was a casket or plug. He called EMPI and the told him they had a past history of carbs that leaked through the castings.

[stugray]

This might be a long shot, but dont carbs need a vent out the top to equalize pressure with the atmosphere or pressure will build in the float bowl?

Any chance the OPs bowls arent venting properly?

Wrong gaskets, backwards, air filter bracket blocking, etc?
The gurgling and spitting is a clue.

[Milkman7286]

Ok guys I finally got around to the carbs again and I removed the carb from the car to install phenolic spacers and here is what I found:
Without being on the car, I can't get the carb to leak on top of the butterfly. However, the same barrel that I have been having issues with all along will leak fuel from the mixture screw hole under the butterfly. I had to coax it to leak (move carb a bit or shake it or tilt it) but it would leak. I couldn't get it to leak if I turned the screw in all the way. Yes the screw does have an o-ring on it as well as the spring. If I tilt the carb backwards a little fuel will drop from the outside of the screw (where you adjust it by hand or via flathead screwdriver)

Obviously the carb isn't tilted when it's in the car, the above is just what I observed. I put in a new float, mixture screw, mixture screw I-ring, and mixture screw spring as well as all new gaskets but have yet to test any of that to see if it will fix the issue. Have yet to test the spacers either to see if percolation was part of the issue.

[jmill]

Clean up around the O ring seat and possibly get some new mixture screw O rings. That's not your problem though. Might be just old, dirty seat or it got smoking hot and distorted. I'm still betting on heat soak.

[Milkman7286]

Clean up around the O ring seat and possibly get some new mixture screw O rings. That's not your problem though. Might be just old, dirty seat or it got smoking hot and distorted. I'm still betting on heat soak.

I did pop some new o-rings on there so we'll see if that fixes it. I also bought some spacers to reduce heat soak so we'll see if those help too

[rhodyguy]

the screws you're talking about, idle air mixture, SHOULD have little metal caps under the springs.

[Milkman7286]

the screws you're talking about, idle air mixture, SHOULD have little metal caps under the springs.

They do, looks to be made of brass maybe? There is a spring with a cap underneath it, and an o-ring underneath the cap.

[rhodyguy]

correct. one less thing to worry about.

[Milkman7286]

All:

Just fired the old girl up with everything mentioned above. Still gurgles. No difference. I still see fuel on top of the butterfly and I imagine it is still leaking from the mixture hole as well. I have a theory that if I put pressure on the butterfly and force it closed a slight but more than it will stop dribbling fuel on top of the butterfly because it seems like when I do this it stops but I could be losing my mind or it could be a coincidence lol.

[jmill]

You installed the spacers too?

This fuel you see on top of the butterfly, can you tell us where it's coming from? The pump jets, the aux vent or from some other location?

We really need pictures to help you.

When you open the butterfly, even slightly, you actuate the accelerator pump. That squirts fuel from the pump jets. There will be one on each throat of the carb.