1974 mercury 650 cooling problem?

albert71 · #1 July 16th, 2002, 07:01 PM

I have a 1974 mercury 650 (3 cylinder) that I just replaced the lower unit. Impeller is new and installed. My problem is that the bottom of the block cools just fine, but the top of the block gets really hot. Also it's not shooting steady stream through the peehole. Does this engine have a thermostat, and if it does can someone tell me where it's at. There's a little hose that goes from the bottom of block to the top. My guess is that this hose carries the water from the bottom to the top of the block. Where the hose goes connected on the bottom it looks like water wants to come out(spitting) but it doesnt. Could this be clogged and if so, how should I unclog it. I have the manual to this engine but it doesnt say anything about that little hose or the thermostat.

I have a picture of that hose(highlighted) at:

http://www.members.aol.com/albert71/650.jpg

Thank you,

Albert

torxdrive · #2 July 16th, 2002, 07:08 PM

that is not a water hose you may not have got the water tube in the pump or the gromet is bad

orca · #3 July 17th, 2002, 03:08 AM

This motor does have a thermostat, it also has a pressure relief valve( Poppett valve) they are both found behind the exhust covers. Suggest thet you get a service manual that will show you the correct procedure to check these items.