Mercury 25HP 2 stroke, (2001) - will replacement Lower Unit fit to my engine

[lovskar]

I have crashed the propeller shaft on the existing Mercury 25 HP, 2 stroke with S/N OT193227, 2001 years model with a Long Rig.

I have now found a replacement Lower Unit and it seem to be very close to the original, but not 100% exactly the same Lower Unit, but very close to it.
The only difference I can see is that there is a track on the driving shaft with an O-ring placed just below the splines and
that the shiftrod on the replacement unit differs in that sence that the original shift rod has a small bend at the top.
The top inch of the shift rod tilts a bit forward as you can see in the attached drawing. View attachment Mercury 25 Y2001.pdf

The Replacement lower Unit seem to be a different year. I dont have any detailed S/N or Year on that one but it looks very close to this one and the shiftrod has no bend on top as the attached drawing here View attachment Mercury 25 old.pdf (dont know if its exactly this one), Otherwise the Lower Units looks just the same and similar water pump and everything else looks the same.

Now to the questions:

1) Will this Lower Unit fit into my engine with a shiftrod without a small bend in the top - and can I get the Latcher into the small whole in the shiftrod anyway ?

2) Why has the shiftrod this form in the top ?

3) If it not fits is it possible to bend the replacement shiftrod to a similar form, IF needed to get into position fully so it will fit and work. The top of the shiftrod tilts forward maybe 5 mm at the top.

4) The other difference is that the driving shaft on the replacement Unit has a track for an O-ring below the splines. The original Driving shaft has no special track for an O-ring

OR do you recommend me to return this Lower Unit and renovate the original one witha new Propeller shaft ?

Thanks for any advice how to move forward on this one !

 

[lovskar]

No Title

I have crashed the propeller shaft on the existing Mercury 25 HP, 2 stroke with S/N OT193227, 2001 years model with a Long Rig.

I have now found a replacement Lower Unit and it seem to be very close to the original, but not 100% exactly the same Lower Unit, but very close to it.
The only difference I can see is that there is a track on the driving shaft with an O-ring placed just below the splines and
that the shiftrod on the replacement unit differs in that sence that the original shift rod has a small bend at the top.
The top inch of the shift rod tilts a bit forward as you can see in the attached drawing.

The Replacement lower Unit seem to be a different year. I dont have any detailed S/N or Year on that one but it looks very close to this one and the shiftrod has no bend on top as the attached drawing here (dont know if its exactly this one), Otherwise the Lower Units looks just the same and similar water pump and everything else looks the same.

Now to the questions:

1) Will this Lower Unit fit into my engine with a shiftrod without a small bend in the top - and can I get the Latcher into the small whole in the shiftrod anyway ?

2) Why has the shiftrod this form in the top ?

3) If it not fits is it possible to bend the replacement shiftrod to a similar form, IF needed to get into position fully so it will fit and work. The top of the shiftrod tilts forward maybe 5 mm at the top.

4) The other difference is that the driving shaft on the replacement Unit has a track for an O-ring below the splines. The original Driving shaft has no special track for an O-ring

OR do you recommend me to return this Lower Unit and renovate the original one witha new Propeller shaft ?

Thanks for any advice how to move forward on this one !

I have uploaded also a photo of the Motor Upper Unit where the shiftrod shoul be fitted in. As you see its the smaller whole here and its 2 wholes after another when you try to fit it in. It the shiftrod then has a bend on top then I guess it will be very difficult to get it into right position with a straight shiftrod. Its very probably so that the whole in the shiftrod then will not be in the right position for the Retainer. I estimate it will then be 5 mm from the original position. THe only way to solve it is to bend the shiftrod slightly or go for the Original Lower Unit with original shift rod to be on the safe side

 

[lovskar]

I have uploaded also a photo of the Motor Upper Unit where the shiftrod should be fitted in.

I manage to install the Replacement Lower Unit today and got the Retainer to fit in the hole in the shiftroid. All gears where OK so it seam to work, but I have not yet tested it.

The gear ratio seem to be similar 2,25:1 as the original when I looked at it


The Original Lower Unit has P/N [h=1]Mercury-Mercruiser 1665-8669T28 GC COMP 25 2S LG[/h]
and the Replacement Lower Unit that I found has P/N [h=1]Mercury-Mercruiser 1665-8668C2 GC COMP 25 2S LG[/h]