Ed Purcell wrote:
> They say the carbs are usually not the problem, but it sure
> looks like mine are messed up. To reinterate, I have
> excellent idle and operation at low RPM. Cutting out
> starts @ about 2K under load. I can nurse it up to about
> 3K max. Also cuts out worse up hill. Thanks again.
Sorry, I don't recall the details of the original post.
Did you not recently install an electronic dizzy? One way that might screw up
your carbs is if a vacuum line got neglected and is now sucking air. Perhaps
you richened them at idle to make it run okay? At speed that air leak would
become less significant so that it would be too rich.
Here's another idea. Your tale sounds vaguely similar to my experience with
the SUs a PO put on my GT6.
I could dial in the idle mixture okay, but at speed it had two features. When
cruising it would miss, especially after it had warmed up, seeming to be too
lean; under full throttle it ran like a racehorse. Playing with the idle
mixture didn't really help. Eventually I figured out that both the springs and
the needles were wrong. The PO had used late-model MGB carbs. The needles
were too thick so it was too lean for cruising. At full throttle the pistons
would hit maximum excursion too soon, resulting in a venturi that couldn't open
any further, which richens the mixture at higher flow rates.
If your carbs haven't been touched then this isn't your problem. But perhaps
you've had a piston spring break? Or a diaphram split?
--
Jim Muller
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