Let me say a few words about leaking fuel on Spitfires. Speaking from
experience, I found that the twin HS2's on my spit would leak for the
following reasons:
1. Floats not adjusted correctly
2. Gunk in the fuel lines causing the float valve to stick open.
3. I have an electric fuel pump that will exert too mych pressure if
the regulator valve is adjusted much over 2.5 psi.
4. The car is parked on a hill so that the detached float bowl is
higher than the carb inner surface base.
5. They just "wanted to".
I was able to finally get all this sorted out with turning down the
regulator, adding in-line filters, changing the fuel tank, and adding
gross-jets. Then I repainted the frame member because all that gas make
the paint on the freshly painted frame crinkle.
Joe Curry
Atwell Haines wrote:
>
> At 05:29 PM 3/12/98, r-james@tamu.edu wrote:
> >Regarding fuel leakage after shutdown from the Spitfire's
> >ZS carb:
> >
> >I have EXACTLY the same problem, and it is at yet uncured. In
> >fact, the other day enough fuel siphoned out on the floor, thru
> >the carb, to make a puddle nearly as large as the car, plus at least
> >a cup in the air cleaner. The tank was full, and a significant fraction
> >of a full tank was gone.
> >
> >I have repaced the float valve (tried two different new ones, and two
> different
> >used ones that seemed to be ok), set the float (more than a dozen times)
> >checked the float for bouyancy (twice). I can't figure it out, but it
> >must be a problem with the float valve. The only way I could make it stop
> >is keep the float set very low (0.975 instead of 0.675 inch!). Then it ran
> >too lean, though.
> >
> >Still, I would like to know why I couldn't fix a simple float valve, or
> was the
> >problem something else. My fuel was coming out of the small port in the
> throat
> >of the carb, not from a leaking carb body.
> >
> >Ray
> >-------------------------------------
> Hi Ray,
>
> Boy you ARE persistant. [Set the floats more than 12 times?]
> Anyone want to hazard a guess?
>
> When mine was leaking, it stopped after a while. The biggest puddle was
> about 12" wide under the car. I thought that it might have something to
> do with fuel pressure, but yours just ssems to be FLOWING out.
>
> Could the fuel be getting past the threads of the float valve? The
> rebuild kit I installed used a metal washer; the grose-jet used a fiber
> one. Maybe some teflon tape on the threads...is teflon gasoline-resistant?
>
> The gas just doesn't flow out of the tank, I don't think. I had the carb
> off for six weeks, with the tail in the air while I rebushed and u-jointed
> my car, and nothing came out of the gas line (and the tank was full).
>
> Has the potmetal on a carb ever become porous?
>
> When you had the bowl off, was there dirt in the bottom? (Mine did for the
> first and second times, but that subsided.)
>
> Atwell Haines
> '79 Spitfire FM96062 UO (On the road again!)
>
> "47.5% of all statistics are made up on the spot."
--
"Thanks to the Interstate Highway System, it is now possible
to travel across the country coast to coast without seeing
anything." -- Charles Kuralt
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