High Reving 1988 Merc 3.7L 2b at Idle

[hitechupgrades]

Installed new 2barrel carburetor on my 1988 Mercruiser 3.7L 4cy today.
Throttle cables working fine, but since it's new carburetor the idle screw likely needs adjustment and I'm not an expert on that. The engine fires right up but it immediately revs extremely high and no matter where the trottle is positioned; the revs stay the same.

Do I just need to adjust the screw near the linkages to lower the idle RPMs?

Should I have the throttle in the neutral position or forward or WOT ?

This is with a Rochester 2 barrel carburetor.

After that...should I then check my air/fuel screw adjustment at the bottom of the carburetor ?

 

[alldodge]

Howdy
Remove the throttle cable from the carb and see if it idles down. If it does, adjust idle to spec. Then adjust the cable so it just fits and then adjust barrel nut one more turn to have it help apply pressure to keep it closed

 

[hitechupgrades]

We started adjusting the idle today after removing throttle cable and it ran a few times, but unfortunately stopped on us. Couldn't get fuel going again. It's almost as if the darn fuel float or needle valve got stuck on us again. It's a new carburetor from National Carburetors out of Florida. They said after the shipping (FedEx overnight) it can often get stuck and thus we tapped on it yesterday and got it to work. But then today, the darn thing seems to be doing it again. Working the throttle manually at the side of the carb, we aren't seeing any fuel coming into the chamber.

 

[alldodge]

Can understand it may get stuck once, but if it does it twice then that would tell me it needs another needle valve. The pressure from the pump should push it open

 

[hitechupgrades]

My issue appears to have resolved itself. Needle valve no longer sticking and was able to settle down the reving too.

 

[MacGod]

Installed new 2barrel carburetor on my 1988 Mercruiser 3.7L 4cy today.
Throttle cables working fine, but since it's new carburetor the idle screw likely needs adjustment and I'm not an expert on that. The engine fires right up but it immediately revs extremely high and no matter where the trottle is positioned; the revs stay the same.

Do I just need to adjust the screw near the linkages to lower the idle RPMs?

Should I have the throttle in the neutral position or forward or WOT ?

This is with a Rochester 2 barrel carburetor.

After that...should I then check my air/fuel screw adjustment at the bottom of the carburetor ?

I have this same issue. When I start it it reves so high scarred me... what exactly did you do to resolve it.

 

[jbcurt00]

Closed