1984 mercury 115

Thedub75

Recruit
Joined
Apr 4, 2014
Messages
1
Hi I just took my boat out on the water and when I put it in to forward I start off slow and then when I start to give it more gas The engine Boggs out. This does not happen every time just sometimes and when it runs it runs perfectly fine. I thought it was the carbs so I sprayed Sea foam carb cleaner into them and put carpet cleaner in the gas to clean the injectors and Jets. I ran about a quarter tank of gas through it and I seem to have the same problem. Any suggestions?
 

Imjus4u2nv

Seaman
Joined
Jun 10, 2013
Messages
57
Re: 1984 mercury 115

I had a similar issue with my 90hp, not sure if I fixed it or if it self corrected, but I had a loose wire going to one of my ignition coils so maybe double check all your wires are nice and tight. Then I drained the carbs, I had a flat head screw on the side (towards the bottom) which drained them. I also did the sea foam workout and the boat worked! No rhyme or reason though. Before that I had an other issue which was the boat revving up when I tried to get on plane rather then bog, and this was a spun hub/prop.
 

wired247

Lieutenant Commander
Joined
Oct 8, 2011
Messages
1,557
Re: 1984 mercury 115

I cant believe putting carpet cleaner in the gas didnt solve your problem.
 

racerone

Supreme Mariner
Joined
Dec 28, 2013
Messages
39,412
Re: 1984 mercury 115

This is fairly typical of the " tower of power " motors.-----Need to find the low speed adjustment needle on front of carburetor upper right hand side.-Open all 3 about 1/8 turn at a time and see what happens.
 

CharlieB

Vice Admiral
Joined
Apr 10, 2007
Messages
5,617
Re: 1984 mercury 115

84, stacked 6 or a 2+2 4 cyl?

As idle passages accumulate crud and begin to restrict fuel flow the motor gets to the point it gets difficult to accelerate well. This is often a sign the carbs need to come off for a proper cleaning. Chemical fixes often fail, they can disolve a little, but they can also dislodge chunks and cause even more problems. Chemicals can be great when used as a preventitive measure, AFTER you properly clean the carbs.

Idle fuel flow is critical to acceleration. The two strokes do not have accelerator pumps (except the 2+2's, and then only for the bottom 2 cyls). Idle mixture must be overly rich to provide that extra measure of fuel necessary for acceleration. Just a bit more than "Best idle speed in gear".

Clean the carbs, adjust the idle mixture.
 

cylo

Cadet
Joined
Oct 12, 2013
Messages
15
Re: 1984 mercury 115

I had a similar problem with evinrude 120 89 model. it would bog on acceleration, but was doing it all the time however half throttle and WOT there was no issue at all. Turned out to be the power pack.
 

racerone

Supreme Mariner
Joined
Dec 28, 2013
Messages
39,412
Re: 1984 mercury 115

A 1984 is likely a " tower of power " inline 6 cylinder.
 
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