Engine or outdrive serial number to select correct water pump kit

[boozer1966]

I’m sure to be ridiculed for this question, but when selecting an outdrive water pump kit, do I use the engine serial number or the outdrive serial number. This is for a 1984 Mercruiser 140 with the MR drive unit.

 

[Bt Doctur]

outdrive

 

[achris]

Drive. But of course that assumes the lower housing is still original. The best way to be sure you get the right parts is to split the drive and look at the top of the drive shaft. If it has a spring loaded pin in the top, it's an MC1/R. No pin, it's an MR/Alpha One....

Chris...

 

[boozer1966]

Thank you.