Idle adjustment, Idle set screw???

8

86Rinker19ft

Seaman Apprentice
Joined
Apr 16, 2011
Messages
38
Hello all, First off the basic info: 1986 Rinker V180, 3.7 Mercruiser (serial # A408965), 3.0 liter alpha one stern drive (yes I know thats not the correct stern drive), 14 x 19p prop (aluminum).

I let the engine warm up today (175) and noticed I am idling a little high (1000-1100rpm). Initially it was around 700 ish at start up, but after warming up and putting it into drive then back to neutral, it seemed to want to hang around 1100? And if I shut it off and turn it back on, it is still around 1100? So I was going to mess with the idle set screw and I looked in the clymer manual I have. It identity's 2 different 2 bbls. Mine is labeled as follows:

GM 2 Jet Rochester
Gold Mercruiser tag, which says: 470/485 1376-5990 A1

The problem I am having is that the manual only shows one screw on the base of the carb for adjusting idle, and I have 2 screws that both look IDENTICAL??? So how can I bump my idle down a bit?
 
8

86Rinker19ft

Seaman Apprentice
Joined
Apr 16, 2011
Messages
38
Re: Idle adjustment, Idle set screw???

Bump, now one has a carb with two screws? Seems like it should be an easy adjustment:)
 
8

86Rinker19ft

Seaman Apprentice
Joined
Apr 16, 2011
Messages
38
Re: Idle adjustment, Idle set screw???

Ok, Thanks to Don and the manual download I was able to adjust the idle today. Took it out, let it warm up and then back the idle down a bit. Now I have a new issue, the Tach. will SOMETIMES start to rapidly fluctuate evn though the rpm is staying the same. I also noticed that the boat did the stahl out thing a little bit around 4000 rpm, I only did it once then didnt really go that high on the throttle again. So any thoughts? Btw, I did swap the carb out for the other one I had which is what really fixed the problem of falling on its face around 2000-2500 rpm.
 
You must log in or register to reply here.
Top