: Hi John

: You want some sort or part of your footpegs to be rigid for bracing so the
: difficulty would be having the space. But 2 pumps side by side seem to fit
: the cross section shape . You need oneway valves on the intake and
: exhaust. The most efficient hook up is to link them to gether with a
: teeter so that when you push one side it lifts the other, then you dont
: need springs and you dont waste that energy. : One thing abt plungers is that they already have a good diaphragm connection,

Erez, thanks for the links incase the plungers don't work.

Mick, it would seem to me that you wouldn't need the teeter or springs since the rubber plunger acts as a spring. Let say you press on the plunger rubber with your foot. The air pressure closes the oneway valve on the bilge line laying in the water and exhaust the air out the oneway valve on the discharge line. Then when you lift you foot off the plunger it springs back out filling with water as the oneway builge valve opens. A vacuum must be created in the discharge line at this time in order to close the dischage valve and I can't really picture that. Then you push the plunger with your foot and the pressure closes the bilge valve and forces water you just sucked in the plunger cup, up through the pressure opened discharge valve line. That may not be correct but it seems like it would work that way. It will be simple to make one to test when I get to it.

Thanks,
John