PDA

View Full Version : sweet 16 inadequate water supply



sctiberio
06-12-2006, 07:53 PM
i have 91 omc cobra outdrive & ford 302 block in my sweet 16. it was running intermitantly hot. i disconected the supply hose from the lake at the thermostat housing and ran the engine for a few seconds with the garden water hose connected. the water would spurt out the end intermitantly from no flow to a 2" or 3" head every couple of seconds. i replaced the impeller and now i get a steady stream of water, only a 1" high head. the manual says for this test that the head should be 2" minimum to 4". it still runs hot, but not as much.
When i had the impeller out i ran water through the out drive to the pump housing from both directions with good flow. i.e. there is no apparent blockage between the intake and the pump and the thermostat housing and the pump.
any clues?
ps: grumpy old mechanic, if your there i replaced both risers and manifolds and now they both run the same temperature.

chappy
06-13-2006, 10:29 AM
Has the boat ever been is salt water? Also, does it have a fresh water flush at the transom on the port side?
Had a similar problem,
Rich:flag-navy

MOP
06-13-2006, 12:04 PM
Have you checked the hose from the drive to the transom shield it may be kinking restricting the flow.

Phil

sweet 16 1966
06-17-2006, 11:57 AM
I am working on the same issue with my boat. Replacing the thermostat today and also have picked us a sending unit to match my SW gauge.
I too thought it was the hose but not suspect the above. Will advise findings later after another trial. I too replaced the impeller again this year but the old one was fine.