Would you do a DIY on a rebuild?

[scjakester]

I dropped my boat off at the shop on Thursday for a minor carb adjustment due to a rough idle that I've been experiencing for 6 months and thought nothing about. Turns out, this rough idle is because the motor is running on 5 and a half cylinders! A thumb size hunk of the top piston on the starboard side has been burned away next to the exhaust. The head looks a little funky too on that cylinder, but I think it will clean up. There is a nasty groove on the wall where a ring scraped it, so I'm sure there will be some machine work needed. I was thinking that I could bore it out a little and use some slightly oversized rings, but the mechanic specifically mentioned getting the cylinder sleaved. I didn't ask him about oversized rings, he just mentioned the sleave.

It is an older boat (1996) and an older still motor (1991 Mercury XL 200hp) it is a carberated motor and there are very few external parts. I am considering soliciting the help of my nephew and turning it into a couple of weekend project and rebuilding the thing myself. The boat mechanic (who has a really good reputation here in Columbia, SC) told me that the motor was very clean and would be worth rebuilding. He also said that he would have to go through it first thing after the rebuild and figure out what made it happen in the first place.

I have a decent collection of hand tools, I've "helped" rebuild a couple of car engines and I'm a pretty good parts swapper. I have little doubt that I could swap out the powerhead myself, but this is a lot deeper than that. Can I get a good manual and break this thing down myself or do you think this is too much of a project to take on without training and experience?

If it's something I can do myself, what parts and gaskets will I need? Who makes the best service manual (tons of pictures!) for the layman? Is there a basic gasket kit and ring kit somewhere? Should I buy the parts from my local Mercury dealer or order them off the Internet? Off the top of my head, I know I'll need one piston and some machine work, and the head cleaned up. Will I need to replace the bearings, or any rods, etc?

I put a couple of pictures here:

http://www.earthroute.com/boat/rebuild1.jpg
http://www.earthroute.com/boat/rebuild2.jpg
http://www.earthroute.com/boat/rebuild3.jpg
http://www.earthroute.com/boat/rebuild4.jpg
http://www.earthroute.com/boat/rebuild5.jpg

Please opine.

 

[Laddies]

Re: Would you do a DIY on a rebuild?

To start with you need a real Mercry manual, I can't tell you if you can do the job or not, read the manual and you will know if your comfortable with it or not. The reason the mechanic said to sleeve the cyl. is because some 200HP are chrome bore and there are no oversize pistons because they can't be bored, some have cast sleeves and can be without a serial number I can't tell which yours is. As far as finding the cause of the problem he was exactly right but the engine has to come down to tell. There are complete gasket sets availabe for the engine and piston, rod and main brgs at Sierra dealers as well as Mercury dealers.