Re: should i buy this??
Use caution when you test-fire it. The impeller will have hardened/taken a set, and if you run it too long like that the blades will likely break, and they definitly aren't gonna pump water worth beans. And you do NOT ever, ever, ever, repeat, ever want to overheat one of these 3-cyl's!!!!
You'll need to replace the impeller before you even think about taking it out on the water.
Hopefully they drained the carbs out and put the motor into storage properly. You may have to rebuild the carbs otherwise.
Check the plugs for rust, spin the flywheel with all the plugs out and see if the crank and pistons move nice and smooth.
Be sure to spray some lube into the cylinders and spin the engine over with the starter before taking compression checks. It's been dry for a long time!
Same time as your compression check, check for spark by putting the plugs back in their spark plug boots and ground the plugs to the block. Should have a fat, blue spark at each when you crank it over.
This motor was OK as far as they went, but you don't want to put it on a large boat and overload, it won't hold up. Much better on a smaller, lightly loaded boat.
And one of the first mods you'll want to do is move the telltale outlet to the top of the block. This was recommended by Merc to ensure that the block is vented and fills completely with water, otherwise they have a tendency to develop 'steam pockets' around #1 cyl then it fries.
Perhaps one of the old-timers here has the TSB about this or some measurements on where to drill the hole. Otherwise, you'd need to pull the cover at the back of the block (cyl block water jacket cover) so you can see where to drill/tap the 3/8"-N.P.T. hole.
HTH, let us know what you find..........ed
