late 80s mercury 115hp specs for setting butterfly positions

[noahsboat17]

I have a late 80s 115hp mercury, engine runs good, but when I throttle up it takes a long time to plane out and get speed. I have removed the carks and will throughly clean them, going to drain the gas etc. I am going to order the service manual for this motor, but it will prob take a few days to get here, so my question is this I am going from top of motor down. #1 carb and #3 carb butterflies are all the way closed, but #2 and #4 carb butterflies are open a tiny bit. how do I make sure I have them adjusted right when I put it back together? I have not worked on boat carbs much, but have a lot of experience with mower, quad and motorcycle carbs. I have worked on motorcycles with 4 carbs and have been successful, but need advice for setting up carbs and linkage. I just bought the boat so not a lot of history, it runs just seems like at full throttle its bogging, should have a lot more power. I will also take a compression test, which I have not done yet. so basically I need advice on how to set the carbs up. Thank you

 

[Chris1956]

Re: late 80s mercury 115hp specs for setting butterfly positions

Normally you would synch the carbs to be closed at idle stop and open at the same time.

If that motor is 4 cylinder/ 4 carb, it is 1990 or newer, I would think. The last IL6 was made in 1989, if I remember correctly.

 

[noahsboat17]

Re: late 80s mercury 115hp specs for setting butterfly positions

Thank you for the info Chris. I was going off the year of the boat saying it was a late 80's. I found the serial # on the mount of the motor, today I will find out exactly what it is. going to get the carbs back on it. Then do all the other little things. Thank you for the help