Motor Running Hot...Still.. Circulating Pump?
 

Replaced the sea water pump last night and took it out. Temp normal at idle and slow speeds (2500rpm), but when I speed up, temp climbs. Got it on the trailer today with the garden hose and same thing, temp climbs with engine speed. I did notice the amount of water volume out the exhaust looks normal at idle, but seems to decrease with engine speed.

Re: Motor Running Hot...Still.. Circulating Pump?
 

What did the impeller that came out of the sea pump look like? Maybe pieces causing partial blockage somewhere in the motor. Does water output decrease with Rpm or just not increase- hose collapsing from suction somewhere?

Re: Motor Running Hot...Still.. Circulating Pump?
 

The old sea pump was fine. In fact, I now have a spare to carry on the boat.
And yes, the water output seems to decrease with RPM increase. All the hoses are new, and I watched them for collapse.

Re: Motor Running Hot...Still.. Circulating Pump?
 

Pulled the cur pump, removed the back plate, it's fine..... Beautiful Saturday and I working on my boat :(

Ahhhhh, the life of a boat owner

Re: Motor Running Hot...Still.. Circulating Pump?
 

I sucked some sand up in my boat a few years ago. I made it back to the dock just as the high temp alarm went off. Did not get it real hot just to the warning buzzer. I changed the impeller and took off all hoses and back flused the system. Put it back together and it still overheated. The problem was the thermostat was damaged and not opening fully. The overheat damaged the thermostat. If you overheated your engine yo may have damaged the thermostat.

Ron

Re: Motor Running Hot...Still.. Circulating Pump?
 

Check for clogs in EVERYTHING. and hoses can collapse, as a boat owner you should know NEW=NOTHING!!!

Re: Motor Running Hot...Still.. Circulating Pump?
 

Checked the t-stat in a pot of water on the stove. It opened fully at 140. Ran the garden hose through every hose, hole, fitting and cooler. Nothing. Went to Auto Zone and bought a $15 temp gauge and put the probe in the other port of the intake and laid it on the back seat. Started motor on the garden hose, temp went to 140 and stayed there on remote gauge. Dash gauge said 160. Brought the rpm's up and dash gauge went to 200, the remote gauge went to 160. Put it all back together and went to the river..... WOT, 145 on remote gauge, 180 on dash.

A bad temp gauge or sender....
Damn, problem seems way too easy to fix for a boat.
Original 1989 Checkmate VDO gauges..... Livorsi gauges was on the list of to do's... Oh Frrreeeeed...


I'm guessing the water volume I was speaking of before is just the way it looks. Probably the same amount of water, just that the increase of exhaust flow makes the water droplets into a fine mist and makes it look like less water when the RPM's are raised.

.

Re: Motor Running Hot...Still.. Circulating Pump?
 

Asuuming you have a bravo 1, did you check the water inlet on the gimbal housing? Often the alum corrodes and restricts the flow. I had that problem and drove me nutz.

Re: Motor Running Hot...Still.. Circulating Pump?
 

Yes I did, I back flushed it by stuffing the garden hose into the inlet hose where it connects to the sea water pump and tuned it on full blast. It took all the garden hose could put out with out backing up and came out a good stream out of the nose cone pick up.

Re: Motor Running Hot...Still.. Circulating Pump?
 

I recently went down this same path - backflushed from sea pump to outdrive and all looked OK. But the problem was the outdrive hose (from transom assembly to lower unit). The hose was collapsing under suction from the sea pump. Water hose expanded it and it looked OK. Just a thought...