On Tue, 7 May 1996 Pschauss@aol.com wrote:
> 2 1/2 years after converting my '80 MGB to HS4s I decided it was
> time to retune them. When I took the lids off of the float chambers
> to check the float levels, I discovered that I have the non-adjustable,
> one-piece floats. The float height is about 1/4 inch instead of
> the expected 1/8 inch. Adjusting the idle mixture, I started with
> the jets at the recommended two full turns down from where they
> were even with the venturi. Checking the mixture using the
> lift pins, it was too lean at this point and it took at least two
> additional turns down to get a proper mixture at idle.
>
> So my question is, how, or should I be adjusting the floats on
> these carbs? I can see how I could set them lower by placing
> shims under the needle valve, but there does not seem to
> be any room to adjust them higher.
>
> I should note that when I tuned the carbs on my Healey (HS6s
> with adjustable floats), the starting adjustment (two turns down)
> was too rich.
>
> Just as a point of reference, I have the timing on the MG set
> at 14 degrees BTDC. The car has plenty of low end torque,
> but seems to fade a bit beyond 3500 rpm. Sometimes I think
> that I detect a hint of a miss between 60 and 65 mph in 4th
> (3300 to 3500 rpm). Plugs, wires, cap, and rotor were all replaced
> over the winter and I also adjusted the valves recently.
>
> Any ideas?
>
> Thanks in advance,
> Peter Schauss
> pschauss@aol.com
> 1980 MGB
> 1963 Austin-Healey 3000 Mk II
>
The floats do not adjust - the jet valve does. If you remove the jet
valve (5/16" I believe), you will notice a washer if there is one there.
Usually when you buy the valve and needle set (or get the grose jets),
you will also receive some washers that are used to adjust the seat
height. I suspect you do not have the washer currently installed, causing
the excess clearance.
David Councill
dcouncil@imt.net
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