1980 Mecury 40hp - Overheating

jayard78

Petty Officer 2nd Class
Joined
Dec 28, 2008
Messages
101
I think now that I FINALLY got my boat in the water with this project motor that it is now overheating. It will run forever when in idle and neutral but about 3 to 5 minutes of actually moving the boat in the water at a higher throttle speed the motor dies out and I smell a little bit of crispy motor smell. It smokes all the time (exhaust) but right before it dies I don't believe that is exhaust smoke. I read up in my repair manual and they say there is a tell tale jet that sprays from the engine to indicate proper cooling circulation from the water pump and I can't say that I remember seeing this stream of water.

Help me to understand the water pumps please. I have been learning as I go an this is new to me. Is a water pump expensive? Can I replace it myself? Do boat owners usually replace these by themselves or rely on a mechanic?

Any other imput about my specific situation is greatly appreciated. It really does seem like the motor is overheating though, b/c after it dies it wont run right until we let it cool, and then the same thing happens over again.
 

tashasdaddy

Honorary Moderator Emeritus
Joined
Nov 11, 2005
Messages
51,019
Re: 1980 Mecury 40hp - Overheating

well if the motor sat with out being use for a period of time, the impeller get brittle and breaks, you realy need a merc service manual, to repair it. is the pump expensive, no, compared to a siezed up motor.
 

jayard78

Petty Officer 2nd Class
Joined
Dec 28, 2008
Messages
101
Re: 1980 Mecury 40hp - Overheating

I have a Selco Mercury Repair manual. Will that do the trick?

Is the impeller a part that is on the waterpump or is it a separate part i may need?
 

jayard78

Petty Officer 2nd Class
Joined
Dec 28, 2008
Messages
101
Re: 1980 Mecury 40hp - Overheating

nm ... i think i can figure this one out.
 
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