Mercruiser Alpha 1 water pump question

[penny lane]

Hello all. First off I would like to say that this site has been quite informative and I have learned alot as a new boater.
Background info:
1986 Mercruiser 3.0 L with Alpha 1 drive gear ratio is 1.98:1
Motor is the 4 cyl carb'ed motor
Power package is in a 19.5 foot Starcraft V191

My question is this:

I have removed the lower unit to replace my melted water pump assembly...yes the whole thing was melted into one big mess compliments the former owner. I have installed everything according to the merc manual that i downloaded plus using a diagram that my merc dealer printed out for me. Is the water tube supposed to fit snugly into the water pump housing, or should it just rest in there loosly. If it is supposed to be firmly placed, what would you recommend to place it firmly as the wonderful manual does not specify this information.

Thanks in advance for your help!

 

[dubs283]

Re: Mercruiser Alpha 1 water pump question

there is a white plastic guide tube that comes with the new water pump kit

this goes in the hole where the copper tube fits on the aft part of the water pump housing

the copper tube should be installed in the water pocket in the upper housing, then when re-assembling the drive halves, the guide tube will aid in aligning the copper tube into the water pump housing on the lower

i hope you also replaced the water pump base assy with a new gasket (it is purchased separately from the water pump kit)

 

[penny lane]

Re: Mercruiser Alpha 1 water pump question

Ok just so I am understanding this correctly...the white plastic tube is just the alignment tube and is not suppost to fit tightly into the pump housing?

And yes, I replaced the gasket and o-ring under the base...purchased the OEM base kit and pump kit...I even got a spare set of gaskets out of the deal as well as several spare o-rings...like the dealer put and extra gasket/seal/o-ring kit in the bag for free.

 

[dubs283]

Re: Mercruiser Alpha 1 water pump question

...the white plastic tube is just the alignment tube and is not suppost to fit tightly into the pump housing?

correct, the copper tube that fits into the upper is the water passage tube

make sure when you put the drive halves back together, the copper tube goes into the guide tube, then all will be good

you should also inspect where the copper tube goes into the upper

that receptacle is plastic, and if it overheated that much, may have melted this too!!

 

[penny lane]

Re: Mercruiser Alpha 1 water pump question

The copper tube is firmly in place in the upper unit and there doesn't appear to be any melting damage there, just the wonderful exhaust soot covering everything on its way out the prop Thank you so much for your assistance.