150 merc. Black max drive shaft length

I am a rookie boater and need some help finding general information on rebuilding my lower unit! My first problem is when i check for a year on the motor I only get the first 4 numbers to match my serial #. Is this correct?
Also I live in the middle of no where Nebraska and can't seem to find any one else to help with my questions so here's another one. What length of drive shaft do I need for my motor? Please email me if you can help!

I know the motor is an 86. I need to know that if I measured 21" for the transom to find a drive shaft is my shaft 20 or 25?
The motor is an xr2 150 v-6. Please help!!!!!

Munsen21

Re: 150 merc. Black max drive shaft length

You talk about rebuilding your lower.If you need gears you will need special tools to install the parts.All gear sets need to be shimmed. Shaft length:Measure from the center of the motor on the transom to the bottom center of the boat under the drain plug.It will be 20-25 or 30.
Call 410=255=4365 ask for parts and they can help identifying your motor. Jerry

Re: 150 merc. Black max drive shaft length

munsen21 said:

I am a rookie boater and need some help finding general information on rebuilding my lower unit! My first problem is when i check for a year on the motor I only get the first 4 numbers to match my serial #. Is this correct?
Also I live in the middle of no where Nebraska and can't seem to find any one else to help with my questions so here's another one. What length of drive shaft do I need for my motor? Please email me if you can help!

I know the motor is an 86. I need to know that if I measured 21" for the transom to find a drive shaft is my shaft 20 or 25?
The motor is an xr2 150 v-6. Please help!!!!!


Munsen21

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A mercury dealer can take your serial number and tell you exactly what the original engine was. (hp, displacement, features, length, etc.) Mercury has a registry of serial # to engine build. The next number in the sequence could be a 5 horse tiller motor.

That XR2 is probably the strongest 2.0 that mercury built. I believe it has the smaller 4 inch gearcase on it. Between the 2, it's a hellova bass bote motor.

With the smaller gearcase, if it's not religeously maintained, and run with good lube in it, like merc high performance, it'll try to put the pinion out the side.


One dealer I know of that is extremely knowledgeable is supreme marine in minneapolis.

hope it helps
John

Re: 150 merc. Black max drive shaft length

Your motor is probably a 20 Inch for your transom size. Two different shaft types were used or can be used. One has a spring loaded preload tip in the end of the shaft the other does not. In any event the shaft length will be around 23.5 to 24 inches from the end of the shaft to the top of the casing if it is a 20 inch. if it is a 25 inch then the shaft will be considerably longer.
If you have no experience in the rebuild of these lowers and without having the tools, I would recommend not attempting the job and simply find a good replacement on Ebay.
Good luck and happy boating.