Zenith Stromberg Help

I've forgotten where all the drillings go on that carb but the symptoms are those of a sticky (jammed open) needle valve on that carb.

Drop the float chamber and investigate. I can't remember if this can be done with the carb still attached to the manifold - from your photo it looks as though it may be possible.

Thanks for the suggestions guys, i'll have an investigate and see what i can find. If it is a Fuel bowl vent, should it be left open and not connected to anything?

The main reason i ask is that on the Left hand carb (not the leaky one), the same hole is connected to the crank case breather. But the breather on the Right side (leaky one) is connected lower down (the black pipe in the pic).

I wonder if your installation is not original.

Putting a float chamber vent into the crankcase doesn't seem very sensible - your situation is a prime example: neat fuel into the sump!

The old Range Rover installation put them back into the air cleaner, I think. I have an old engine which may be sufficiently complete for me to work it out. I'll have a look over the next few days to see.

In the meantime, just leave it open to atmosphere.

One pipe goes to the rocker-cover breather via a flame trap and is connected to the carb throat so ingests and burns any oil vapour, the other (smaller one) vents the fuel bowl and, if the needle valve fails, fuel.

Should have a pipe on each leading to the ground - mine lead to just behind the front x-member. If they vent directly to air and decide to leak neat fuel can sit on the valley which can then prompt the rapid evacuation followed by the use of an extinguisher through the radiator grille!

Ah right, so would you suggest that the carb on the right hand side of this photo:

I have the pipes and they just vented the float chambers to atmosphere well clear of interesting places such as Andy describes.

You need to check the connections on the LH carb. They seem to have become interchanged from your description(difficult in view of the the sizes I would have thought).

The float chamber vents are the ones in the inlet adaptors from the air cleaner - as marked with the arrow on your photo. The crankcase breathers (rocker cover) go via the flame traps to the connection on the main carb body nearest the manifold - as in your photo for the RH carb. On the LH carb that'll likely be on the bulkhead side of the carb.

Dougal, just to clarify, when you say LH carb, you mean the one on the left hand side of the car, but right hand side of the photo?

Yes. The crankcase breather should connect to the stub on the bulkhead side of the LH carb(RH in photo) much closer to the manifold as on the leaky carb.

Sound like a rootes application ( Hillman?) some had a breather pipe back to the air filter Derek

Unfortunately work has meant that i've had to sideline the landy for a few days, but when i get back to it i'll let you know how i get on.

Thanks to everyone for all the advice.

You were quite right, it was a sticky float needle. I dropped the float chamber as suggest, which was just possible without remooving the carb, and nothing seemed out of place. So i just pushed the float up and down a couple of times to check it was free. When i re-assembled the carb, it seemed to work fine. So i dont know what caused it to stick, but at least i know what to do next time!

Thanks again.

|| So i dont know what || caused it to stick, but at least i know what to do next time!

Crud, which you disturbed. Repeat every 100,000 miles. :-)