DANMAS@aol.com wrote:
> Changing the stroke won't fix the problem.
Note that you aren't really changing the operating
stroke length, as long as the carbs are assembled
and attached.
The fuel pump lever doesn't "return" fully
every time. The amount it returns depends on how
much fuel is displaced on the stroke by the
diaphragm. It's usually not very much.
As was mentioned, the lever "loads" the diaphragm,
and the spring pressure forces the diaphragm back
against the pressure in the carb float bowls. When
the float bowls are full, the diaphragm doesn't
fully return. This is normal operation.
You will notice if you hand-prime a fuel pump
that the stroke is long, until the system is
primed, and then the stroke is nil, the lever
doesn't engage anything until the end of it's
stroke.
In normal engine operation, the stroke is
somewhere between nil and maximum, depending on the
fuel demands of the engine. Lengthening the "stroke"
will increase peak capacity of the system, but
this is only needed if your fuel pump is already
bottoming out which I don't suspect it is.
--
Trevor Boicey
Ottawa, Canada
tboicey@brit.ca
http://www.brit.ca/~tboicey/
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