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MG MGB Technical - My B won't start

I began to have problems at higher speeds (engine miss) in 3rd gear and it would stop when I shifted into 4th. It got worse until it started missing in total with very little power. I replaced points with an electronic ign. and replaced the carb. diaphram. Now it fires, and starts for just about enough gas that would be in the carb. I am getting spark from all plugs. The fuel filter is good. Presure from the fuel pump in just under 4psi. My next thought is to pull the carb and check the needle, floats etc.. for trash. Additionally, I think my rich/lean allen screw in the air piston in the carb is striped, no mater how many times it is turned there is no movement with the pin. Sorry for the length, as you can tell I am a little frustrated, all ideas are welcome.

Neel
N Choate

I had the exact same thing occur with my Weber DCOE. It drove me nuts for two weeks.

Turned out that a very tiny sliver of debris got caught in one of the idle jets. I have no idea how it got
past the fuel filter and screen mesh...but perhaps it was a bit of gasket paper from the top cover.

I think that you are on the right track in that you should clean the carb(s). Blow-out every passage with
a shot of carb cleaner and re-assemble with surgical cleanliness.

Don't know how you should proceed with the stripped allen screw adjust, however, except to get new
parts for it.
Daniel Wong

I battled this a few years ago. I could drive about a mile at a time at one point. In other words, just far enough to leave you uncertain if the problem was solved, but stranded if it wasn't. It turned out to be dirt in the inlet side of one of the float chamber lids (SU's). Opening the float lids immediately after it's died may give you a clue to where the block is. One or both float chambers will be empty if it's upstream.
Steve Postins

This thread was discussed on 29/05/2003

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