1972 merc 1150 carbs

[Vision91]

I know this engine has been a big issue with a lot of ppl on here but was wondering if there is a tool for getting all three carbs in sync with each other. I know the tool has mercury in it so it might be hard to get...what I'm trying to do is tune all three carbs within the same mixture settings cause its hard to do by ear and my service manual just says factory setting is one turn out then turn to the left till it chugs the screw back the other way and have it between those two points...sry if there are misppeled words typed these on my phone , thanks for the help if anyone can

 

[BatDaddy1887]

Re: 1972 merc 1150 carbs

....answer #27 has the instructions for a link n sync:

http://forums.iboats.com/showthread.php?t=278358&page=2

 

[Chris1956]

Re: 1972 merc 1150 carbs

There is no tool used on the carbs. There is a trick that works for folks without expert mechanic skills. Have the motor running in the water, in gear and warmed up. Now adjust the carbs idle mixture to achieve max idle speed and smoothness. Now the carbs are in synch, but the idle mixture is likely too lean for smooth accdeleration. Open the top carb 1/8 turn and try to accelerate. Repeat with mid carb, and then bottom carb, testing acceleration after each adjustment. Repeat sequence if necessary. Eventually you will hit a mixture that gives smooth acceleration and reasonable idle.

 

[Vision91]

Re: 1972 merc 1150 carbs

i did do that as well chris and i got it to where i like it at slightly rich which never hurts and im not to worried about max rpm on it. the tool that im talking about is real me and my dad had one a few yrs ago dont know what happened to it what it does is read the suction from the carbs sorta like taking the complete carb of and putting your hand over the hole, it just reads what the suction is. but now my issue is the timing by the looks of it time to tear into it and see

 

[Chris1956]

Re: 1972 merc 1150 carbs

Vision, Motorcycles use sets of vacuum gauges to synch the carbs. However, Merc has never (to my knowledge) used any tool to synch carbs.