What adjustments are available on this 2150 carb? I don't see any idle/ fast idle/ mixture adjustments?

 

They are way up under the front bowel, and if the carb has never been rebuilt, then they are covered over by aluminum.

 

Ahaa... carb was rebuilt by previous owner. Now to get to those screws. Slight lope after warming up 4-5 minutes. Will not idle unless you physically keep it reving for 4 plus minutes. Choke does fully close when cold. After ~ 5 minutes off reving it'll idle but at 1200 RPMs. Thanks Dave.

 

If it runs ok after it is warmed up, then make the choke close more by loosening the round black piece on the passenger side of the carb, and turn it in the "richer" direction.

If you still have trouble with the idle, you might want to take the round gold piece off behind the carb in the picture(EGR) and make a temporary block off plate out of aluminum. If it idles better you probably need a new egr valve.

 

The fast idle, pull-down & choke related adjustments are around the back, the curb idle is the long, hex-head screw with the spring on it, in the foreground of your photo. If this needs much adjustment, the TV rod setting (the tubular linkage coming up from behind the engine, connecting to the throttle linkage) for the trans needs to be checked afterward, in case the transmission line pressures have altered with the idle adjustment.

If you search '2150' in the Fuel Injection/Carburation forum, FMC400 has done a couple of detailed articles on choke set-up & general tuning of these carbs.

 

If you are going to play around with the idle screws, I recommend sliding a 6" length of hose over the screw heads. Then you don't have to try and get a screwdriver under there.

 

That's a good idea that I have used myself. Otherwise they have these expensive springy tools that flex and bend to get to the screws.