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MG MGB Technical - Zenith carb advice please!?

I am working on a 1977 MGB that has been sitting for several years. I have siphoned most all of the old gas out of the tank and have put several gallons of new fuel in to replace it. The engine turns over and wants to start. The fuel pump wasn't working at first but a couple of taps with a rubber mallet got it to purring away as well.

The problem seems to have something to do with the carb. I have the air cleaner pulled off of the Zenith, which is stock except for having a manual choke kit to replace the original. When I pour gas into the air intake it will fire right up but them soon dies. It does not seem to be getting any gas from the gas line, but there is gas coming out of that line when I disconnect it from the carb.

Any advice, any thoughts. Am I missing something really simple? I turn to those with the wisdom of the ages to help me out.
David Quigley

Have you pulled the fuel supply line at the carb and verified that you are indeed getting fuel to the carb? (Aim the fuel line into a collection can and then turn the ignition on. If there are no blockages in the fuel line from the fuel pump, you should get a good stream of gas going into the can. Just be very careful!

Have you replaced the fuel filter(s)?

It's probably something VERY simply!

rick

rick ingram

Sounds like a stuck float valve in the carburator float chamber. Sometimes gentle tapping on the bottom of the carb will free it up, or you may have to take out the half-dozen screws holding the float chamber bottom of the carb on and wiggle the floats.
Tom

There is also a separate filter in the carb
fuel bowl inlet. You might remove the fuel
feed line to the carb and blast some carb
cleaner into this filter.

Other causes of starting up, then dying

1. The autochoke is sticking on and the
mixture is way too rich. This will cause flooding.
Do you smell gas? Pull the plugs and see if
they are wet.

2. The zenith needs the aircleaner on to run
properly, although I think it should still idle
without it.

3. As Tom says the float valve could be
sticking. Probably best to replace it along
with the carb gaskets, diaphragm.
Ronald

This thread was discussed between 23/04/2004 and 24/04/2004

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