Question on a serial number of old Merc 500

[Chinewalker]

A 65hp of that era would be a model 650. Serial indicated 1965. Short shaft indicates a fairly rare beast. Not many motors that large in a 15-inch transom size. Doesn't necessarily mean you can retire on it, but it is certainly worth more than scrap value. Some of the guys into old fiberglass boats might have an interest in it if you want to unload it.

 

[merc850]

Before you start getting into the 50 hp check the distributor bearings by turning the pulley to see if the bearing(s) are seized (arrow)
, if they are that's why the timing belt is missing; looking at the condition this motor is in it looks like the motor has been sitting outside without a cover - you should buy a manual http://store.oldmercs.com/category_s/829.htm to help restore it.
This site is full of guys that know this motor http://johnsoldmercurysite.com/phpBB3/index.php

 

[Opelman03]

Thanks everyone for all the tips and info. I think I have enough to see whats up with these guys. Will keep everyone posted on the progress. Lots of great information on these forums.