Which waterpump would you use?

[sutor623]

Okay fellas my lower unit project is nearly finished. I am assembling the water pump now. Here is a pic of the three waterpumps that I have.



The first one has no grommet at the top where the shaft goes through, and is plastic. The water input tube is messed up because some genius tried to shove it up without the water input line in the right place.

The second one is aluminum, and my preferable choice, since the base that I'm using is aluminum, but the rubber grommet used at the top has a little tear in it, but nothing that would create a leak.

The third one is the new 'el cheapo' that came in my kit. It has no rubber at all at the top, and there is a gap between the metal and plastic on the top. It seems almost impossible to me for that housing to create a vacuum.........

None of these pumps seem to be snug around the driveshaft. There is a rubber piece that goes over the top of the waterpump that helps with that. My question is, if it was your motor, which housing would you guys use? I thought that the tops would sit a little tighter around the driveshaft, but I guess when the impeller goes in it prevents any leakage from happening when the vacuum effect starts with the water?

 

[Faztbullet]

Re: Which waterpump would you use?

Only use the one with the straightest bottom as they like to warp....

 

[emckelvy]

Re: Which waterpump would you use?

Use the new one. It doesn't need a seal, Merc re-engineered that part long ago. The ribs cast into the impeller do all the sealing, at the top on the pump insert, and at the bottom on the pump plate.

BTW the older plastic Merc housing on the right could be de-burred, cleaned-up and reused, but it'd need a new rubber grommet. And I expect the stainless insert is worn as well, all the better to use the new one.

BTW the plastic Merc pump likely got chewed up because a water tube 'guide sleeve' was not used. Almost impossible to get the lower unit up and engaged into the water tube without using a guide sleeve. You can see the results of not having one! Mercury part # 29804 if you don't have one. This guide sleeve just slip-fits into the pump housing, after the rubber grommet is installed.

Be sure to use the black rubber 'slinger ring' in your pump kit, this ring (as the name implies) 'slings' sand, silt, & other debris away from the top of the pump. After pump installation is complete, just slide the ring all the way down the driveshaft, to the top of the pump.

HTH...........ed

 

[sutor623]

Re: Which waterpump would you use?

Hey guys, thanks a ton for all of the input that ya'll have given me on this lower unit. Both of you fellas have given me some great advice, and I thank you!! Its nice to know that I have experienced people that I can count on when doing things that are a bit new to me. I would rather ask questions and get the job done right, rather than doing it incorrectly and learning from my own guesswork/ trial and error.