In article <200108180355.XAA22232@chelseamsl.com>, Donald H Locker
<dhl@chelseamsl.com> writes
>Sounds to me like the springs in the overrun valves have relaxed. The
>throttle blades in later SU carbs have a spring-loaded poppet valve
>that prevents excessive manifold vac in case of overrunning condition
>(engine braking.) If the valve gets leaky, or the spring gets weak,
>the normal manifold vacuum will open the valve sufficiently to keep
>the engine speed high, until the speed vacuum drops. If you have
>these overrun valves, you could try shimming the spring a bit to see
>if it helps. Or do what I did, and solder them up solidly. (It was
>an emissions control trick and doesn't otherwise affect engine
>performance.)
>
>Oh. You're in the UK. I may be all wet on this then, but it might be
>worth a look.
Thanks for the suggestion. I'll certainly have a look, but first I'm
going to have to find a crib-sheet. I wouldn't recognise any of the
components you mention by name. Is there a labelled exploded diagram
on the web anywhere?
ATB
--
Mike
Michael Hargreave Mawson, author of "Eyewitness in the Crimea"
http://www.greenhillbooks.com/booksheets/eyewitness_in_the_crimea.html
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