61 Gale 15hp cooling problem

[Hoser]

I have a couple quick questions for this motor.
Firstly its mod and ser number are:
Mod# GG18737D
Ser# 26x854903

I just (today) replaced the impeller with a new one from laings outboards, part# 3002, if this helps.

Now the problem I have is that it pumps great then starts slowing down to a fine mist almost, thats when I stop the motor. Now if I let it sit for a minute it will pump like crazy, then slowly stop again, I let it run thinking that it was possibly a thermostat problem, but it started to get hot so I shut it down, at no point did it get so hot as to make steam.

 

[F_R]

Re: 61 Gale 15hp cooling problem

It doesn't have a thermostat, so cross that off your list. Are you running it on a boat or in a bucket? That could be your problem. Water should be a considerable spray out the exhaust relief hole in the back at slow speeds. It more or less just runs out at high speeds.

 

[Hoser]

Re: 61 Gale 15hp cooling problem

Yes, was running it in a barrell, I made sure it was deep enough to cover the pump by about 2-3 inches water. Wjats odd is that after setting for a while it would pump like crazy then slowly peter out to nothing, I even tried it in gear, same thing. Its acting like the pump is starving for water but the inlets look clear. I just started it again and counted, took 5 seconds to run out of water.

 

[F_R]

Re: 61 Gale 15hp cooling problem

Not a "normal" problem, hard to diagnose from a distance. Start by taking the pump back apart for a second look.

Is the aluminum pump housing worn, especially around the center? There comes a point where just replacing the impeller is not enough.

There is a small hole drilled at an angle through the pump outlet, to the cavity around the drive shaft. Purpose is to keep the cavity filled with water and provide a water seal around the shaft. Is the small hole clear?

There could be something floating around in the cooling system, like a piece of rubber from an old broken impeller. That, you just have to search till you find it.

 

[steelespike]

Re: 61 Gale 15hp cooling problem

Be sure the water inlet is clear.It seems like thje pump is full of water when you saytart it but can't get enough for some reason.Be sure the water is deep enough like you were sitting still with it on a boat.

 

[Hoser]

Re: 61 Gale 15hp cooling problem

Thank you steelespike and imported_F_R, I will dissassemble it again tomorrow and check the items you recommend and post my results.


Thanks again,

Hoser

 

[Hoser]

Re: 61 Gale 15hp cooling problem

Found the problem, upon disassembly I found that the rubber coupling insert on the water tube became pinched thus restricting the flow, and being a plumber I re-worked it so that now you can slide it together first, then the drive shaft and finally the shifting rod. its working perfect after 15minutes of high idle in neutral.