Water Pump Impeller Replacement?

[kipawakid]

I'm the proud owner of a 27' 1988 Sea Sundancer with twin 205 HP Mercruiser 4.3L engines. Outdrives are Alpha One Gen One Oyster White. Temp gage on dash indicates starboard engine is getting hotter (200 degrees) than port engine (145 degrees) at idle speed, but both operate in the 145 degree range when cruising. My guess is the outdrive water pump impeller needs to be replaced. Boat is in the water on a lift that does raise the outdrive comletely out of the water. I am thinking about replacing the impeller while it is on the lift. My manual indicates I do not need to remove the entire outdrive from the boat, just separate the drive shaft housing from the gear housing. Any advice if this is possible would be appreciated.

 

[Fishermark]

Re: Water Pump Impeller Replacement?

Welcome aboard!

Yes - it is possible. It can be a little more difficult to get the lower unit back on with the upper still attached. There are a few things you need to line up and hold in place while you lift it in place. It seems like it would be pretty tricky to do with the boat on a lift. Where would you be standing and working?

 

[kipawakid]

Re: Water Pump Impeller Replacement?

Thanks for the reply. It looks like most of the work would have to be done sitting on the edge of the dock, as the prop is at dock height while the drive is in the trail position. I think I could rig some planking between the dock and the lift floats to have a make shift platform.

 

[Bondo]

Re: Water Pump Impeller Replacement?

Ayuh,... The oil port, where the quad-ring goes will allow water into the lower unit if ya dunk it while doing this operation ya know....

Atleast if ya pull the Whole drive, 'n split 'em on the dock,...
It'll be a sealed unit while stabbin' it back onto the boat...

 

[Don S]

Re: Water Pump Impeller Replacement?

I would suggest you get the boat trailered and other maintenance done at the same time.
The outdrives need pulled yearly in order to grease the coupler splines. Without getting greased yearly, you are looking at a strong possibility of the splines stripping out, then you will be looking at pulling the engine to replace the coupler.
There is other maintenance that needs to be done also, like ujoint greasing, checking the alignment, checking the bellows for water and gear lube, and greasing and cleaning up the old grease from the gimbal bearing. All should be done yearly.
While the drives are off for doing the above maintenance, it's a lot easier to change the impellers.

 

[kipawakid]

Re: Water Pump Impeller Replacement?

Certainly everything you mention is correct. I am kicking myself for not changing them at the end of the season while I was doing the regular PM. It won't happen again! The drives were off prior to the start of last season, and the bellows were all replaced. It sounds as if I should put it back on the trailer and in the barn to tackle this task.

 

[Don S]

Re: Water Pump Impeller Replacement?

My manual indicates I do not need to remove the entire outdrive from the boat,

Missed that before, you must have one of those aftermarket junk manuals. The OEM manual sure never says things like that.

Here, download the OEM manual for free, then you will know how to do things the right way.
http://www.4shared.com/document/zz_5pj9o/Service_Manual_06.html

Here is one for the engines too.
http://www.4shared.com/document/1FdjddET/Service_Manual_07.html

You might find this one handy too.
http://forums.iboats.com/showthread.php?t=387864

 

[kipawakid]

Re: Water Pump Impeller Replacement?

I did purchase hard copies of the same manuals you identify from the Sea Ray dealer. Page 3D-10 is where I was starting. Perhaps I am in the wrong section or not understanding what I am seeing.