93 115hp outboard problems

[Jimbaird]

I have a 93 Johnson 115 hp outboard with problems.I started last weekend and after 2 minutes running it seized. I could not get it to release for a while but when it did it started back up. Since I was in a tournament I used it for two more days. It ran okay but with somewhat reduced power & rpm.I got it home and checked compression an I have one cylinder with 50psi.The motor has 490 hrs. on it and I wonder what my options are.I am mechanically inclined and I have a buddy who is a mechanic with 20 yrs. experience. Is it possible that we could do a powerhead exchange with a rebuilt?How do I determine what happened to the old motor to prevent problems with the rebuilt powerhead?Any suggestions? Jim Baird

 

[Jimbaird]

Re: 93 115hp outboard problems

I took the head off the motor and it looks like I lost a ring.

 

[emdsapmgr]

Re: 93 115hp outboard problems

It's not unusual for these crossflows to throw a ring. You need to determine why so that your new or rebuilt powerhead does not do the same thing. Could be an overheat or fuel/oil starvation. I'd pull the carb apart that feeds that bad cylinder and visually check the jets on the side that feeds that bad cyl. Check to see if there is any restriction/debris in the throat of each jet-esp the high speed jet. If the engine runs lean on a cyl it will get hot and crack a ring and you get the result you see. Do you see any evidence of aluminum transfer from the piston to the cast iron cylinder walls?

 

[Jimbaird]

Re: 93 115hp outboard problems

There is aluminum on the end of the piston and aluminum deposits on the head. The cylinder wall is scored in one place but there does not seem like there is any aluminum on the cylinder wall.