Raw water pump in OMC saildrive.

[Chris Patterson]

Can it be true that you have to pull the motor in one of these animals to change the raw water impeller? From every indication of the parts blow-up, it appears that is the case. This is a Zephyr, OMC saildrive in an Oday 28 by the way, and I have the boat on the hill. It recently had an impeller put in at a local "boatyard", and now it pours water inside while underway.
Oddball contraption..

I could post a picture later if it made any difference..

 

[Barnacle Bill]

I used to install these engines when they were popular and I do believe that you have to pull the engine. The lower unit fits through the hole from the inside of the boat and then the head is put atop that. Don't know why water is coming in unless your boat yard did not connect up the water tubes properly. Do you have an owner's repair manual for this engine? I believe I do and I could scan pages out of it if that would be a help to you.

 

[Chris Patterson]

Thanks Bill. Today I went ahead and snatched the engine out of it, and cleaned it up. Still don't know exactly where the water is coming from, it was just filling up in the adapter plate. Hoses look fine, and nothing visibly wrong. The process of tearing it down on the bottom looks "challenging". Especially without any funny papers. I've got my hands on an exploded parts diagram, and of course it's been marginally helpful, but a shop manual would be the saving grace.

(How DO I get myself caught up in these odd projects?)

 

[anchorclanker]

The impeller is right above the lower gear unit, right above the prop shaft, and is a sub assembly of the lower unit. It is slipped onto the vertical driveshaft and so turns as the engine turns. If you have water pumping out from near the powerhead, you dont have a bad pump, but have a leak somewhere. But as long as its out, change the impeller.

Generally, you remove the bolts holding the lower gear unit to the intermediate housing. The shift shaft is either splined, and will slip off, or coupled somewhere up above. You should be able to figure it out looking at everything, especially shift linkage, as you take it apart. Just take the bolts out of the lower unit and start watching. The main drive shaft is splined into the power head and will simply drop out. Once the shift is disconecto the lower should drop away (be careful to catch it), or may need a little gentle persuasion. On install, carefully check shift operation as its going together, so you know its going into forward and reverse (and neutral), with the control, before you have it all bolted back together.

 

[anchorclanker]

Oh, also grease all the splines on the shafts with waterproof grease before reassembly. Further, there is a water tube, and often times an exhaust tube, that you will have to be careful to watch for alignment of, on reassembly.