Postby Hasbeen » 06 Apr 2008 00:05
Alan, the main jets, in the throat of your SUs, are lower than the
float chamber gasket, or the overflow. You must have petrol running
from these, if its overflowing from the top. No wonder its rich.
Your float chamber needle, & seats should be replaced, making sure
the alloy washer between the seat, & the top of the float chamber is
replaced. This should fix the problem, provided fuel pump is still
original. Clean out the fuel lines from the pump, to the carbys
while you are at it.
Having said that, a car can sometimes run quite OK, while driving,
with leaking needle & seats, as the amount of petrol getting past
them is no more than the engine uses when under way. The problem
occurs when stopped, idling, as the engine no longer uses the amount
of fuel leaking into the float chamber.
If your pump has been replaced, or modified, the problem can become
much greater. SUs are designed to run with no more than 2 PSI fuel
pressure, & many of the replacement pumps have a higher pressure
than that, depending on the instillation. Find someone who can test
your fuel pressuer for you, & if its below 2 PSI, fit the new needle
& seats.
If its too high, we have ways of fixing that too.
Hasbeen
