1975 Mercury 115 Horsepower (1150) Idling Issue

[76tower]

Hey everyone! I have a 1975 Mercury 1150 6 cyllinder. I rebuilt the carbs a few years ago and changed the trigger and the engine idled and ran great. It still idles great out of the water. But when its in the water it sometimes has a very low idle, and I need the use the fast idle lever to prevent it from stalling and on take-off. Any suggestions on what I can do?
I read somewhere that those little hoses on the carbs should be taken off and the fittings should be capped. Can that be an issue? Thanks.

 

[Bosunsmate]

Re: 1975 Mercury 115 Horsepower (1150) Idling Issue

Not sure which little hoses you mean.
You can back the idle mixture screws out to increase your idle speed, do it evenly though

 

[Bosunsmate]

Re: 1975 Mercury 115 Horsepower (1150) Idling Issue

Not sure which little hoses you mean.
You can back the idle mixture screws out to increase your idle speed, do it evenly though

 

[Chris1956]

Re: 1975 Mercury 115 Horsepower (1150) Idling Issue

I assume you mean the small rubber hoses on the carb covers. Those will not affect idle. Idle speed should be set to 900 or so, using the idle stop screw on top of the distributor. Of course, dirty carbs or misadjusted carb idle mixture can play havoc with idle speed.