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Re: SU H4 float height

To: "Kevin Sullivan" <kevins@khoral.com>, <mgs@autox.team.net>
Subject: Re: SU H4 float height
From: "Paul Hunt" <paul.hunt1@virgin.net>
Date: Fri, 17 Mar 2000 19:49:22 -0000
With an SU you should be able to weaken the mixture right off to stalling
point, the float level is not as important as jet/needle size.

Leaky throttle shafts would require *richer* needles to compensate, not
weaker.

Are you sure you have the right jets?  There are two sizes, .090 and .100.
The smaller is used on the 4-cyl MGB, for example, and the larger on the V8.

PaulH.

----- Original Message -----
From: Kevin Sullivan <kevins@khoral.com>
To: <mgs@autox.team.net>
Sent: Friday, March 17, 2000 6:45 PM
Subject: SU H4 float height


>
> Here's a post that's not about BMW and Rover :)
>
> I know how I'm _supposed_ to set the float height (7/16" bar method), but
> that is not working correctly.  I'm running _way_ too rich.  New correctly
> sized needles (AO) and jets (I measured them, dial calipers are cool!) New
> throttle shafts nicely not letting in extra air.  The carbs are the
> correct carbs for the engine.  The needles that were in it originally were
> incorrect and it didn't run too well, _much_ too lean at high speed
> cruise, these things were _huge_, and mismatched to boot!  The AO needles
> are the lean spec for the MGA 1600, since I'm at 5000 feet altitude.  They
> are much richer than the needles that were in there.  The PO may have put
> in superlean needles to compensate for the old leaky throttle shafts?  No
> fuel in the floats, so they should be OK.  The float needles are closing
> fine.  Either the floats are floating at the wrong level or the fuel's
> getting in some other way, perhaps between the jet and the jet bearing.
> If I remove the dashpot covers and look into the jets, how far down should
> the fuel level be?
>
> Let's see -- what else do you need to know?  Yes, of course I drove the A
> in to work today, it's beautiful outside.  And I'm wearing my green MG Car
> Company t-shirt.
>
> --
> Kevin Sullivan             kevins@khoral.com
> Khoral Research Inc.       www.khoral.com/staff/kevins/mgstuff
> Albuquerque NM USA
>
> 1960 MGA           "Baby"
> 1957 Magnette ZB   "Pup"
> 1959 Magnette ZB   "P2"
>


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