how do fat sack pumps work? I have never been around them and was curious because i might buy some fat sacks next spring. thanks for answering this stupid question!

go to wal-mart and look at an aerator pump...that's all a fat sac pump is. they work one way only (non-reversible) you have to switch the fitting to either end to fill/drain.

Two options. <BR> <BR>1. Impeller type works just like the raw water impeller on your boat motor's cooling system. A splined impeller runs in an eccentric circle causing it to suck water on the intake side and push water on the discharge side. <BR> <BR>2. Aerator type spins water, centrifugal forces develop pushing water out of the outer housing and pulls the water through the center. Air doesn't weigh enough to make centrifugal forces high enough to keep it primed so it has to be flooded to begin the pumping process.