"Wayne.B" wrote:


The fuel pump on my generator is a small electric unit. I don't know
if it is positive displacement ot not but reducing the supply diameter
fixed the problem for sure.

Is it not true, that in "lift" mode, the pump is lifting less weight
of fuel in a small diameter line?

If the volume per unit of time is the same, then the amount of work output is
the same. It would be lifting more fuel at any given instant, but lifting it
slower. The differential pressure across the pump would be less... this is what
I usually think of as 'load' on a pump. If for some reason, your fuel system
was designed around a given flow at a given differential pressure, then
changing sizes could indeed screw it up.

But the raw physcs doesn't explain everything. Thank you for the cautionary
note... sometimes machinery can act very oddly. One might almost swear it's...
alive!

Fair Skies
Doug King