Hi,
I have a 1980 Spitfire with dual SU HS4 carbs. I noticed while trying to get
to run correctly that the front fuel bowl had gas coming out the top vent hole.
Figuring that it was the needle valve sticking, I replaced the needle valves
and floats in both fuel bowls.
The front bowl (second in fuel line) contined to overflow. I thought that
there may be a crack or something in the lid, so I dug out different lid, put
the new bowls and valves in the lids, made sure the float adjustment is
correct.
These lids have vent tubes, which I have connected with fuel hose - above the
carbs.
Well, gas is coming out of the vent hose connected to the vent tubes - not
sure which carb is overflowing at this point as I did not think to disconnect
them until after I stopped working on them for the evening.
The fuel line now has a T-connector to get gas to both carbs. Previously, the
rear carb had a fuel pass through.
I have a mechanical fuel pump, not original. But one sold by one of the big
vendors - don't remember which now.
Can the mechanical pumps put out too much pressure? The pump has been on for a
few years and it has run correctly in the past.
Assuming I haven't botched installing the needle valves and floats, is there
anything besides excess fuel pressure that would cause the bowls to overflow?
Thanks,
Roger Elliott
1980 Spitfire
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