1986 1987 or 1988 115hp Mercury carburators - rebuild myself?

hokiepoq

Seaman
Joined
Oct 9, 2006
Messages
70
I have a 115hp Mercury outboard, an in-line 6, on my boat that I just rebuilt the transom. It sat for a long while before I rebuilt the transom. I took it out this summer to run it and it worked well except it wasn't at full power the whole time. Seems like it was at 2/3 power while I had the throttle all the way down; then moments later it was jump up to full power (from what I could tell) and run a while. It ran smooth while it was running, just not at full power the whole time. I figure the carburators probably need to be rebuilt. Is this a do-it-yourself job? I change the water pump impeller last year myself so I can do somethings, but timing and aligning things up just right scares me. Any advice?

Thanks!
 

rndn

Commander
Joined
May 20, 2007
Messages
2,323
Re: 1986 1987 or 1988 115hp Mercury carburators - rebuild myself?

It's a do it yourself job as long as you have a manual. Buy one at "http://www.outboardbooks.com/".
 

achris

More fish than mountain goat
Joined
May 19, 2004
Messages
27,468
Re: 1986 1987 or 1988 115hp Mercury carburators - rebuild myself?

That's not a difficult job... The devil is in the detail. Pay particular attention when you put them back on to the linkages between the carbs. Make absolutely sure that all 3 start to open at exactly the same time. Other than that, just work clean and replace the manifold gaskets.

BTW, these are my favourite engines, I love them. Treat her nice. :D

Chris.........
 

Chris1956

Supreme Mariner
Joined
Mar 25, 2004
Messages
28,102
Re: 1986 1987 or 1988 115hp Mercury carburators - rebuild myself?

Hokie, You may have a fuel pump issue instead of, or along with your dirty carbs. To determine this, have someone pump the primer bulb while running at high speed. If the manual pumping of the fuel keeps the motor running at full speed, rebuild the fuel pump.
 

hokiepoq

Seaman
Joined
Oct 9, 2006
Messages
70
Re: 1986 1987 or 1988 115hp Mercury carburators - rebuild myself?

Thanks for the advice guys. Sounds like a good winter project. I found that taking lots of pictures helps me get things together back right.
 

lovesboating

Recruit
Joined
Jan 20, 2010
Messages
5
Re: 1986 1987 or 1988 115hp Mercury carburators - rebuild myself?

I have a 115hp, and what I did was get the manual, and rebuild kits a clean place to work on them, and carb clean and an air supply.
I did one carb at a time and replaced all fuel lines and also replaced the fuel pump.
Man it runs great, just pay attention to detail and the book you should be ok.

J.T
 

achris

More fish than mountain goat
Joined
May 19, 2004
Messages
27,468
Re: 1986 1987 or 1988 115hp Mercury carburators - rebuild myself?

I have a 115hp, and what I did was get the manual, and rebuild kits a clean place to work on them, and carb clean and an air supply.
I did one carb at a time and replaced all fuel lines and also replaced the fuel pump.
Man it runs great, just pay attention to detail and the book you should be ok.

J.T

Another happy customer. :D:D:D:D...
 

arsenalpsu

Petty Officer 1st Class
Joined
Dec 1, 2008
Messages
290
Re: 1986 1987 or 1988 115hp Mercury carburators - rebuild myself?

Are we sure this is due to dirty carbs, what if he's getting intermittent spark in 1 cylinder? If you did run her lean for a wile you may want to do a decarb as she most likely ran hot. Don't want to risk getting stuck rings or detonation due to carbon build up.
 
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