hi guys. heres one to ponder. first of all i will relate the new parts i have putn in my 3.0 liter /cobra outdrive. screen impeller kit with housing backplate and gaskets. watertube fromgimel housing totheoilcooler and from there to the thermostat housing as well as thermostat and gasket.my problem is this. when i test for water flow on muffs i get good flow and it will sit and idle for hours at145 degress. when i put it in the lake i get no water flow period. the impeller shaft is not broken and does turn in correct direction. anyqne had this prob. i would sure appreciate any or all the help i can get on this one. oh yes the screen is clean .