Cannot throttle up 1988 Mercury 115 horse 6 cyl.

tlamos

Cadet
Joined
Aug 31, 2010
Messages
13
1988 Mercury 115 will not throttle up

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Two summers my boat did not get put in the water.I started it up seemed to run fine until I brought it to the Lake,it idles fine but when you throttle it up it dies out.Brought home took all the old gas out put in fresh gas same problem.I then took it to a boat shop they tore down all the carbs and cleaned them.These carbs were rebuilt 3 summers ago by a mercury dealer.I also had all hoses and primer ball replaced by the dealer.Put it back in the Lake same thing happens.I then played with primer ball I noticed the ball did not stay hard
so I purchased a new one intalled it same problem.Once I start to throttle up the engine will start to die I will hit the choke and sometimes it gets me past the dead spot,once I get past that spot it runs very strong. I also rebuilt fuel pump,I then took it back to the lake it ran perfect, better then it has ran for a long time.I thought my problems were fixed.A couple days later I took it out again it started the same problem over again. The only thing I did was gas it up. Anybody with any ideas that I can try?
Confused in Vermont
 

usskydvr

Chief Petty Officer
Joined
May 27, 2009
Messages
494
Re: Cannot throttle up 1988 Mercury 115 horse 6 cyl.

A stumble from idle to WOT is usually the carb idle being too lean. Try to adjust the idle richer, by 1/8 turn at a time. Test each time.
 

tlamos

Cadet
Joined
Aug 31, 2010
Messages
13
Re: Cannot throttle up 1988 Mercury 115 horse 6 cyl.

Would that be on each carb? Also the1/8 turn would that be in or out?I'am not that smart when it comes to engines,but with the rates the boat shops get I need to try something myself. Thank You for your help
 

roncoop75

Petty Officer 1st Class
Joined
Jun 23, 2010
Messages
229
Re: Cannot throttle up 1988 Mercury 115 horse 6 cyl.

Turn the screw out for a richer mix, which is what you want, if that's the problem anyway.
 

usskydvr

Chief Petty Officer
Joined
May 27, 2009
Messages
494
Re: Cannot throttle up 1988 Mercury 115 horse 6 cyl.

Also do it to all the carbs at the same time.
 

njrextreme

Petty Officer 1st Class
Joined
Mar 11, 2010
Messages
228
Re: Cannot throttle up 1988 Mercury 115 horse 6 cyl.

Your carbs should hold a prime. The primer should be rock hard. Take a look and see if gas is coming out the front of the carbs.
 
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