Weber 40s leak from throttle shaft after shutdown

[74superTN]

So I've noticed that if I go on a long drive, my dual weber 40's seem to seep a little and drip on my engine tin after the engine has been shut down. It doesn't happen quick, it usually takes about 5 minutes or so for it to actually show up. Any ideas? I've check my floats and my fuel pressure.

1980 Vanagon, type iv dual weber 40s
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73 Thing
80 Vanagon Westy

[madmike]

your fuel is boiling in the float bowls,, can be fixed by installing some insulating gasket 's search the subject
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'Black Ice'Drag Buggy 'Turbo'
Rail Buggy 1915 turbo
76 Drag/Street bug 2180cc 'Turbo' 11:85 @113 mph"If I go any faster I'll burn up the Hamster" ,gets 28 mpg. also 10/09/22 11.90 @115 mph
"If I'm ever on Life Support,UNPLUG Me, Then Plug me back In see if that Works"

[74superTN]

Any other options other than phenolic? I have access to lexan, kydex, and composite at work..
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73 Thing
80 Vanagon Westy

[udidwht]

Whats your fuel pressure at?

Jetting?

Distributor?
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1972 Westy Hardtop/Type-4 2056cc
96mm Biral AA P/C's~7.8:1CR
Headflow Masters New AMC 42x36mm heads w/Porsche swivel adjusters
71mm Stroke
73 Web Cam w/Web solids
Dual 40mm IDF Webers - LM-2 - 47.5 idles/125 mains/190 air corr./F11 tubes/28mm Vents - Float height 10.45mm/Drop 32mm
Bosch SVDA w/Pertronix module (7.5 initial 28 total @ 3400rpm)
Bosch W8CC plugs
Pertronix Flamethrower 40K coil
S&S 4-1 w/Walker QP 17862
3 rib 002 Trans
185R14 Hankook tires

[74superTN]

[madmike]

Don't know if Lexan will work?
might just try a cheap electric fuel pump
_________________
'Black Ice'Drag Buggy 'Turbo'
Rail Buggy 1915 turbo
76 Drag/Street bug 2180cc 'Turbo' 11:85 @113 mph"If I go any faster I'll burn up the Hamster" ,gets 28 mpg. also 10/09/22 11.90 @115 mph
"If I'm ever on Life Support,UNPLUG Me, Then Plug me back In see if that Works"

[udidwht]

How much fuel are we talking about here?

It isn't entirely unusual for Webers to do this after shutdown.


You will end up with fuel on the outside of these carbs. That's a given.

Float height correct? 10-11.5mm with gasket in place ball NOT depressed.

Fuel pressure 3.5 max?

Carb top gaskets not blocking air bleed holes?
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1972 Westy Hardtop/Type-4 2056cc
96mm Biral AA P/C's~7.8:1CR
Headflow Masters New AMC 42x36mm heads w/Porsche swivel adjusters
71mm Stroke
73 Web Cam w/Web solids
Dual 40mm IDF Webers - LM-2 - 47.5 idles/125 mains/190 air corr./F11 tubes/28mm Vents - Float height 10.45mm/Drop 32mm
Bosch SVDA w/Pertronix module (7.5 initial 28 total @ 3400rpm)
Bosch W8CC plugs
Pertronix Flamethrower 40K coil
S&S 4-1 w/Walker QP 17862
3 rib 002 Trans
185R14 Hankook tires

[69BahamaYellow]

" Carb top gaskets not blocking air bleed holes? " X2 on this one. Sometimes when the gaskets are punched out, the vent/bleed holes still have the blanks left in the gasket, and this will cause fuel to siphon out of the bowls and down the venturi, where it can bleed out the throttle shafts. Only happens 5-10 minutes after shutdown, when the fuel heats up.

[69BahamaYellow]

" Carb top gaskets not blocking air bleed holes? " X2 on this one. Sometimes when the gaskets are punched out, the vent/bleed holes still have the blanks left in the gasket, and this will cause fuel to siphon out of the bowls and down the venturi, where it can bleed out the throttle shafts. Only happens 5-10 minutes after shutdown, when the fuel heats up.

[74superTN]

Update: Phenolic blocks installed, no more issues. It was the manifolds heating my carbs after shutdown
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73 Thing
80 Vanagon Westy