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Not really my line of expertise....just playing around with different pumps on the race mini...it had a double ended pump (from a Jag)....when I tested it...one side runs faster than the other!
Wondering why!!!
Second question...is this unit just two pumps screwed to the center piece??
Have taken it apart yet.....will wait to hear what others think!
Cheers
D

Jag pump is two inlets and two separate pump s connected to a common outlet.

There are a couple of one way valves and a strainer in the housing so that you can pump from either tank without cross filling the other.

Assuming you are testing with the pump in the fuel circuit on the car I would suggest that unless you have a tee piece that splits the supply from the mini tank(s) feed into both pump inlets then that is the reason you have one running faster than the other.

If you are only running one side of the pump, you should really have the other inlet blanked, the one way valves are ok but never 100%.

If you are testing off the car, then the other reasons for slow operation come into mind, worn or badly set points and corrosion on the pump rod area or rings.

Points have been replaced....it does appear to work well....just testing on the bench with the outlet sealed.....I thought it should stop pumping after the pressure builds.
Checked a few other pumps and they all behave the same...even a new one. They don't shut off when you have the outlet blocked.
Wondering why one side runs faster than the other!

Unless there’s a liquid in there it won’t stop pumping. Air is too compressible and won’t affect the one way valves.

Oneball wrote: ↑Wed Jul 01, 2020 4:00 pm Unless there’s a liquid in there it won’t stop pumping. Air is too compressible and won’t affect the one way valves.

Thanks
That makes sense....think this is a decent pump...still not sure why one side is normal and the other side runs faster!

Dermott, I haven't had experience with the double bungers that you have but I've found the springs in them set the output pressures and it's against these pressures that the points are 'tuned' to cut in and out. So while maybe not the issue here, I'd suggest checking the springs are on spec and also matched.