At 10:47 AM 11/12/04 -0600, you wrote: >My question is: Do these have built in internal check valves to prevent back >flow? >Mark Jones +++++++++++++++++++++++++++++++++++++++++++++++++++++
Mark, I had the same concern when designing my parallel pump system. I don't know what my pump numbers are but they are the $29 units from Wick's. I think they are more now but you get the point. Anyway, I hooked the two pumps together "output" to "output" and tried to use one pump to reverse flow pump through the other. Neither pump allowed reverse flow. After that test I eliminated the check valves I had planned to install. My system uses two parallel pumps and wing tanks only. My fuel pressure guage reads about 6 pounds pressure with one pump and about 7 with the other pump. These were supposes to be the 3 to 5 pound pressure pumps. Because of that I installed a fuel pressure regulator set at 4 1/2 pounds to feed the carb on the 0-200. I've never had a problem in 108 hours now. Anyone thinking of going wing tanks only really should consider a backup power system for the fuel pumps. My backup battery saved my bacon at 12 hours when a bad connection in the master switch circuit dropped out my main electrical buss. A simple flip of a switch brought the pumps back on line. More detail if anyone is interested. It's not simply hooking up an extra wire. Larry Flesner
