Over Heated! Yamaha 25HP 2 cycle, Where do I start?

[floridaboytoo]

I have a 1998 Yamaha 25 HP 2 cycle outboard. My son over heated the motor, I was not with him so I don't know how long it ran without water. When I got to look at the motor I found the impeller had gone bad.I replaced it and was able to start the engine. When it started it was running VERY VERY rough and it seemed water was seeping out places it shouldn't, it was getting hot rapidly so I shut it off. Where should I start my diagnosis? What service manual should I get? I am pretty handy with a set of tool and a manual but have never worked on an outboard.

 

[99yam40]

just like any other motor it needs good compression ,good spark at the proper time( timing), and proper fuel to air ratio to fire properly test what you can to start out with and then look into the fuel portion.

Compression would be my guess has been messed up by the overheat. Blown head gasket or scored cylinder,stuck rings.
Where is the water coming out of?
Is water getting into the combustion camber?

 

[floridaboytoo]

Thank you very much ! Does anything or any area need to be cleaned of possible debris from the rubber impeller pieces before I start it again? I will try and start it again and take careful notes as to the questions you asked.

 

[99yam40]

test things