28 PCI leaking carb woes ....

[NikC]

Hi All

So I spotted a bit of a fuel leak issue from my carb a couple of weeks ago so bought a kit and rebuilt the carb.

All went well, runs great ... but just spotted that the leak seems to be still there ....

Pic below shows (with the arrows) where its leaking:

It seems (and I may be wrong ...) that I notice this issue most when I half open the throttle when the engine is not running (so when I'm round the back with access to the engine), and the only times I've really noticed it are when the accelerator has been pumped prior to starting the car or when i manually fiddle with it ... If i hold the throttle open manually with my hand about half way, I can see the fuel slowly start to appear.

Could it be that the leak is really just as a result of the engine not running and there been nowhere for the gas "to go" ? Or is there something more sinister occurring ?

Cheers

Nik

[60ragtop]

needs throttle shaft bushings
_________________
Rick
Certified Mechanic by the State of Michigan in 1977
ASA certified in 1987
Certified Hunter Wheel Alignment Master Technician 1986

[NikC]

[60ragtop]

most just send it out to be rebushed from a carb rebuilder.
But you might be able to buy a rebushing kit.
Where are you located?
_________________
Rick
Certified Mechanic by the State of Michigan in 1977
ASA certified in 1987
Certified Hunter Wheel Alignment Master Technician 1986

[NikC]

[60ragtop]

can't help you out locally then
I go to the hardware store and find something close and re work it to fit.
sometimes you can find a bronze, plastic or nylon bushing that is close
_________________
Rick
Certified Mechanic by the State of Michigan in 1977
ASA certified in 1987
Certified Hunter Wheel Alignment Master Technician 1986

[NikC]

OK thanks.

Let me crack open the spare carb I have and see what I'm after

Nik

[Snort]

It's probably true that your throttle shaft needs to be rebushed but that is not the original source of your fuel leak. More likely is that your emulsion tube is cracked, broken or loose where it fits into the center of the venturi. Fuel drips onto the throttle shaft and flows out the sides of the carburetor. Take a look at a 28PCI diagram and you will see that this joint is below the normal level of the fuel in the float chamber. Typically, this will leak while the motor is running and it will leak after the motor stops until the fuel level in the float chamber is even with the joint or crack.

[NikC]

[Snort]

Unless it's badly mangled, you should be able to repair it. Looking at the diagram more closely, I should have pointed you to the emulsion tube housing rather than the tube itself. A small amount of epoxy on a cracked housing or a fuel-safe sealant to correct a loose fit in the carburetor have worked for me in the past.

[NikC]

Damn the metal is soft in the tube housing ....

Gonna need another donor carb now to replace it

[747frieghtdog]

Gas will come out of the shaft when gas flows down the carb after pumping the accelerator.

Most of the 28PCI's do this from my experience.
_________________
55 Oval