Changing piston ring in 87 115 Evinrude

blhum

Recruit
Joined
Oct 14, 2009
Messages
4
I have low compression in one cynlinder and would like to replace piston ring and hone cylinder. Is this something I can do myself? I have some mechanical ability, but would need some advice on how to do this.
 

wilde1j

Vice Admiral
Joined
Apr 15, 2002
Messages
5,964
Re: Changing piston ring in 87 115 Evinrude

Get a copy of OEM shop manual to see what's involved.
 

bktheking

Vice Admiral
Joined
Jul 29, 2008
Messages
5,057
Re: Changing piston ring in 87 115 Evinrude

What are the comp readings just so we know what we are working with? And there is more to it than just doing one ring, if you are going to the work of re and reing the powerhead plan on doing everything else, all the rings, maybe bearings, a full gasket set.
 

mikesea

Lieutenant Commander
Joined
Oct 1, 2006
Messages
1,830
Re: Changing piston ring in 87 115 Evinrude

I agree with the total rebuild suggestion,because,the whole engine needs to be torn down to machine 1 cylinder,you will get grit and all kinds of crap through the engine by trying to "sneek "out 1 piston,which still requires you to split the crankcase,at that point your 1/2 there
 

emdsapmgr

Supreme Mariner
Joined
Dec 9, 2005
Messages
11,551
Re: Changing piston ring in 87 115 Evinrude

Mike is right on. No point in installing one new ringset only to run the possibility that one of the other old ones fails a month later-and your are into another complete teardown. These crossflow carbed engines are not complicated. Armed with the factory service manual and some resolve, you can get through it.
 

petryshyn

Commander
Joined
Oct 3, 2001
Messages
2,851
Re: Changing piston ring in 87 115 Evinrude

How low is the compression? If decarbing doesn't help, I doubt that you'll get by with just a hone and ring job. You'll be boring and putting in an oversized piston....:(
 

blhum

Recruit
Joined
Oct 14, 2009
Messages
4
Re: Changing piston ring in 87 115 Evinrude

There is about 50 lbs of pressure in the #1 cylinder and a good 100 lbs in the rest. I believe it might be from the previous owner running the mix too lean. The motor has seen better days and I guess I was hoping to squeeze just a little more life out of it.
Thanks for all the advice at least I have a few months to think it over.
 

bktheking

Vice Admiral
Joined
Jul 29, 2008
Messages
5,057
Re: Changing piston ring in 87 115 Evinrude

Or a few months to rebuild it :D
 

blhum

Recruit
Joined
Oct 14, 2009
Messages
4
Re: Changing piston ring in 87 115 Evinrude

Okay I?m going to get started on this. I see several different publishers of shop manuals, like Seloc and Clymer. Does anyone have any suggestions on a certain manual that is more user friendly?
 

SparkieBoat

Captain
Joined
Aug 17, 2009
Messages
3,643
Re: Changing piston ring in 87 115 Evinrude

unless you just want to rebuild the motor, I would buy a good used one, seems to be plenty of them out there
 

noelm

Senior Chief Petty Officer
Joined
Mar 8, 2005
Messages
761
Re: Changing piston ring in 87 115 Evinrude

forget the Clymer and Seloc, it was mentioned way back to buy a genuine (OEM) manual, you are going to need it, one cylinder will not be low compression from running the oil mix too lean, it may be from a lean burn from a dodgey carby, or something, but oil mix NO! you will need to be a bit more than "handy" as a mechanic to get this motor up and running as good as new, but it is not beyond the scope of a patient and skillful home mechanic who has the genuine manual and is prepared to follow it, and listen to advice from here without cutting corners.
 

emdsapmgr

Supreme Mariner
Joined
Dec 9, 2005
Messages
11,551
Re: Changing piston ring in 87 115 Evinrude

You need the original factory manual from the original publisher, Ken Cook Co. in Milwaukee. 414-466-6060. Call them, give them your credit card and they will ship it out to you.
 

blhum

Recruit
Joined
Oct 14, 2009
Messages
4
Re: Changing piston ring in 87 115 Evinrude

Okay, I just finished putting my first 10 hours on the re-build. I took everyone's advice, i.e., getting the OMC shop manual and doing the complete engine. It turned out once I got into the powerhead I found a lot of additional problems such as scored cylinders, broken rings, and worn pistons. It took a lot of time and patients, and some help from the local marine machine shop, but to my surprise it runs great. Thanks to everyone for helping me out.
 

bktheking

Vice Admiral
Joined
Jul 29, 2008
Messages
5,057
Re: Changing piston ring in 87 115 Evinrude

Wowsers, that has to be a post record, an actual reply to a message from 10 months ago, bravo on your rebuild :D :D :D
 
Top