1984 90 HP ETLN overheating.

I just changed my impeller and thermostat, and my motor is over heating.

Buzzer was going off and couldn’t run above 2000 rpm prior to the change, but the head didn’t feel that warm when the buzzer was sounding I could touch the head and it wasn’t that hot.

The weird thing is the head quite a bit feels hotter now than before I changed things, also the tell tale stream doesn’t seem as strong.

When I changed the impeller I rotated the shaft clockwise, also applied some lube to the pump housing and it went to gather real easy.

I didn’t change the poppit valve, but it looks clean.

After returning from the river I took the thermostat housing off and hooked up the hose to see if I was getting good water flow, a couple seconds after starting the motor the water started flowing but seemed to be pretty warm.

I checked the plugs and they look good no signs of water in the cylinders.



So any ideas?

Jeff.

[boats.net]

The alarm could be the low oil warning, check oil level sensor.
May need to replace complete water pump, may need to pull cylinder head and exhaust plate to clean water passages in engine block.

I just pulled the head cover off again and tried blowing air threw the ports, I also drooped the LU blew air threw the water intake tube and didn't get much air flow thru the water ports at the head. The lower unit is Free flowing no clogs.

So with the lack of good air flow should I take the head off and inspect the water ports?

Thanks Jeff.

Took the head off and the water passages are ok, also used compressed air threw the exaust and it is flowing good.

Also oil level sensor is good jug is nearly full and have a green light on the dash.

Jeff.

I might have fixed the over heating problem, I took the lu back apart to check the water pump one more time.

While I had it down I went to get a gasket and decided to bring my new impeller with me to match up with another one, well my impeller I bought some where else was aprox 1/16 taller and about the same wider.

So I got the other impeller put it all back together and ran it on the ears, the head never got above 130 degrees Fahrenheit even with a little high idle. The thermostat is marked 50 degrees Celsius which is 122 degrees Fahrenheit.

So I will try it on the river in the morning.

Jeff.