2000 Johnson 100hp commercial - hole in piston

[CharlieBegin]

Hi all,<br /><br />Don't be too hard on this Newbee please. But I recently aquired the above outboard at a goverment auction for short money. All I know about it is, the Army Corp of Engineers owned it and that it didn't run. So, after getting it home, I took the heads off and found all piston tops are carboned up and one piston has a 1/4" hole in it. The motor turns freely. I didn't try to start it. <br /><br />I have a few uneducated guesses on where to start. But would rather not start spending money based on my limited experience. Could anyone offer an opinion on the best way to proceed. <br />Thank's

 

[tashasdaddy]

Re: 2000 Johnson 100hp commercial - hole in piston

step one get the engine specific manual. kencook.com. study it. you're in for a complete tear down and rebuild. good project, and the greatest help here . welcome to i boats, the university of boating as i like to call it. now do your home work, and get ready for the time of you life. i hope you can operate a wrench, if not you'll learn how. post back .

 

[CharlieBegin]

Re: 2000 Johnson 100hp commercial - hole in piston

As suggested, manual has been ordered . Will check back in once studying has started. Thanks for pointing me in the right direction Chief.

 

[mikeyzx2]

Re: 2000 Johnson 100hp commercial - hole in piston

Chucky, sounds like them engineers don't know much about an outboard. They probably lugged it do death, so to speak. The hole in piston is from preignition, stay with us on this project when you go to tackling it. <br /><br />Other than the hole in one slug, how'd the bores look? Any scoring or scuffing of the walls? Since there's no choice but rebuild, DO make sure that the cause of the failed piston is fixed or it'll happen again. <br /><br />Have fun and keep us posted...Mike