Checking out a 50 hp Force

[captmello]

I'm considering a boat with a 1996, 50 hp force motor. The boat is stored in an unheated indoor facility. I most likely will not have water available to run the engine for any amount of time.

I was thinking, however, of doing a compression test. I realize the test may not be totally accurate on the cold, perhaps fogged motor, but it couldn't hurt.

What compression numbers should I expect to find? Would running the engine for 15 sec. to burn off the fogging oil be a good or bad Idea? I realize this isn't good for the impeller.

What else would you guys recommend? I've never owned an outboard, but I'm good with motors.

Does anyone know if there are owners/service manuals available for downloading?

Thanks.

 

[pnwboat]

Re: Checking out a 50 hp Force

Ideally you'd want to see 120+ LBS compression reading with no more than 10% variation from the lowest to highest. Brand new motors are in the 140+ lbs range. If readings are lower than 100LBS across the board, then I would assume the motor may need new pistons and rings. It's hard to really make good call on this without actually examining the cylinder walls, pistons, rings etc. Starting and running the motor even for 15 sec. will show you how the motors acts, which may give you an indication of other problems. Better to run it in a tub or on muffs, but sounds like you don't have that option. Not sure if running it for 15 sec. to burn out the fogging oil will have any affect on the compression reading.

I haven't seen any manuals specific to the Force to download. There are OEM manuals available, and also from SELOC and Clymer. I have SELOC and Clymer. I prefer the Clymer. My experience is that the OEM manuls are first choice, them Clymer, then SELOC. Check out Iboats and ebay for the manuals.