More motor blues

Carl

Well-known member
Staff member
Good news: carb and fuel pump rebuilt and running great.
Bad news: motor not peeing.
Hot Water is coming out the rectangular vent on the back of the shaft but not out the pee hole.
I ran a pipe cleaner up and did not seem blocked on that end.
When thermostats stick, do they stick open or closed??
I really hate to pull the thermostat, last time I did I broke a bolt and had to rethread the block slightly larger. Im worried to even mess with that bolt.
 
Hadn?t tried yet. I?ll give that a shot a little later.
Good to know it?s probably not the thermostat. Thanks.
 
Carl said:
What is this opening? This is where hot water was coming out.

That is the discharge when the motor is at idle speed. Discharging above the waterline decreases the amount of "backpressure" the water pump is working against. Midrange throttle and above, the water will discharge thru the center of the prop, where it encounters a negative pressure, pulling the water thru the system.

A thermostat can "fail" either open or closed. However a "stuck" thermostat is often stuck open from sand or debris holding it open. Thus the open position is the most common occurrence. The cooling passageways can also become plugged or partially plugged, causing incomplete cooling all around the engine.

The discharge should be warm, but not hot. Spa tub warm, not coffee hot.
 
It did seem to have more water coming out of that vent at idle than when running back to the dock.
It was hot, but not so hot that it hurt, not coffee hot.
So it sounds like there is water moving in the system, just no coming out the tell-tale.
Is that correct?
Either way, sounds like I need to drop the lower unit & replace the impeller and check the tubes for blockage
 
Carl said:
It did seem to have more water coming out of that vent at idle than when running back to the dock.
It was hot, but not so hot that it hurt, not coffee hot.
So it sounds like there is water moving in the system, just no coming out the tell-tale.
Is that correct?
Either way, sounds like I need to drop the lower unit & replace the impeller and check the tubes for blockage

I would sooner suspect a blockage/partial blockage in the engine block, not the supply tubes.
(16) Outboard cooling water - YouTube

But yes, start at the source (water pump) and work your way thru the system.
 
Sounds to me like a weak impeller. How old is it? Over time the fingers will begin to stay in their bent position and not make good contact with the housing resulting in inadequate pressure to fill the water jacket and force water out the indicator hole. Make sure the line between the water jacket and indicator hole is clear of blockage. If it is then time to replace the impeller.

Eric
 
"Sounds to me like a weak impeller. How old is it?"

not sure [whistle]but its old. [laugh]
 
Last edited:
As you probably read, I just replaced my impeller and everything associated with it (bought the kit and it came with extra stuff). When I looked at the old impeller, it looked fine. Replaced it and the amount of water peeing is significantly more with the new one in there. Was worth doing.

If this latest issue came after the motor work, is it possible they disconnected the pee line inside the motor and forgot to replace it? Probably not but might be worth a look if you haven't already.

Mark
 
I did all the work on the carb myself.
It was a lot easier than I expected.
 
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