Iam looking to put vm28 pumpers on my.gpz1170 and was wondering how the pumps work do.they drive off a vacuum source? If so where does the.vacuum source come from on a gpz
They work off a diaphragm that is activated off the throttle linkage which momentarily supplies extra fuel via a nozzle in the venturi .
Every time you open the throttle the diaphragm pumps fuel so don't sit there with the fuel tap on turning the throttle without the engine running as it can flood the engine if done to excess.
