1975 225 OMC

[Scott Danforth]

Sorry I get the impellor would keep the drive cool, but my question is why bother with the raw water pump if the impellor in the drive is supplying water? What am I gaining?

Without the impeller in the drive, the exhaust going thru the drive will overheat the drive

A crank driven pump would not draw through the OMC drive. You would end up with a pickup

 

[Rranger]

Without the impeller in the drive, the exhaust going thru the drive will overheat the drive

A crank driven pump would not draw through the OMC drive. You would end up with a pickup

I get all that Scott, just don’t see the advantage of adding a crank driven water pump to cool the engine.

 

[kenny nunez]

In your post#14 you appeared to want a belt driven pump. The choice is yours.

 

[Scott Danforth]

I get all that Scott, just don’t see the advantage of adding a crank driven water pump to cool the engine.

With your drive, there is no advantage. The drive can't take enough power to need more cooling water flow

 

[Rranger]

Thanks men appreciate the answers. One more question I have the drive stripped down to replace the impeller and in this parts picture the drive was missing these two metal washers part number 21 which asks the question are they necessary? The drive performed great on a test run and no issues with the tilt. I ordered two, got my parts and missing one so have to reorder and another three day delay. Better safe than sorry so will wait unless its 100% they are not needed.

 

[kenny nunez]

The washers and spring were originally used as a ground to ensure the lower gear magnets a negative charge. Later on there was a stainless ground strap added between a pivot cap bolt to the bolt that mounted the rubber bumper. If you do not have the strap be sure to add something similar. If for a micro second loss of negative charge while on plane you will shear off one of the shafts or break a clutch spring in the lower.
Do not worry about the washers but be sure to have a strap like I described.

 

[Rranger]

The washers and spring were originally used as a ground to ensure the lower gear magnets a negative charge. Later on there was a stainless ground strap added between a pivot cap bolt to the bolt that mounted the rubber bumper. If you do not have the strap be sure to add something similar. If for a micro second loss of negative charge while on plane you will shear off one of the shafts or break a clutch spring in the lower.
Do not worry about the washers but be sure to have a strap like I described.

Thank you again, it does have the strap so I guess I’m good to go.

 

[Scott Danforth]

Check the splines on the 3-piece vertical drive shaft. If the are pointy, get new shafts.

 

[kenny nunez]

Pay attention to #s 35 & 47. Those are the weak link that SD is referring to.

 

[Rranger]

Will have a look at that and I guess if I’m basically changing all the upper/lower unit seals I will do prop and ball gear drive shaft also.. Probably in there tighter than Toby’s -$=. Yeehaw. Hopefully it and the vertical driveshafts are ok.