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MG MGB Technical - SU carb - sticking float needle valve

Hi All,

An annoyance on my 77 BGT. After having refurbished the twin SU's (HIF? I can't remember) using a kit, the car runs much better. (It's actually the second time I've done it ain the 5 years I've had the car, and is usually well-worth the effort).

However, when the car gets hot, one of the (NEW!) float valves has a tendency to stick (the rear carb), resulting in fuel leakage out of the overflow pipe.

Has anyone ever had this problem before? Are the new needle valves likely to fail so quickly? It could be a bit of dirt I guess, but I've had the carb off again to clean and fix the problem, but now it's back.

Any comments gratefully received...

Thanks,
Dave.
Dave Taylor

Dave
I've had problems with this over the years, and having HIFs it's a pain to do something about as the carbs have to come back off.
I asked about the alternative 'Grose' valves on here and a lot of people didn't seem to think they were any better than the originals.
At someones' suggestion I fitted a Malpassi, filter/pressure regulator about 700 miles ago and have had no further problems [touch wood], I have an electronic fuel pump and I think the pressure was too high for the float valves to cope with.
On another car I've had a slight problem this spring with a weep from the overflow of an HS6 which was reconditioned by Burlen a couple of years ago, so maybe the quality of some of the needles is crap??
Ron
R. Algie

Sorry should have said the Malpassi is marketed under the name Filter King.
Ron
R. Algie

A clarification on Grose Jets. As per prior discussion here and elsewhere, a concensus of opinion seemed to be that those made more than about 10 yrs ago were apparently made "better" (materials, care in production?) than those which have emerged since. Several folks (myself included) who have 10+ yr old grose jets have had few, if any problems with them. Those purchasing some recently seemed to have a higher correlation of problems in use than us old grose jet users have. FWIW.
Bob Muenchausen

This thread was discussed on 30/04/2006

MG MGB Technical index

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