I have a Briggs Intek 24 hp twin that only wants to idle. New gas, plugs, air filter have been installed. The throttle and choke linkage seems to be working. When you push the throttle lever to increase rpm the engine seems to labor and won't speed up. Whats going on?

Before you get more into that engine I would suggest trying new gas especially if its been sitting for a while. Then I would try running some carb cleaner through it and see if that settles things down. If there is any water in the fuel it can cause those type of issues so try the simple fixes first then if all else fails go to the harder fixes.

Besides the service manual you can view parts diagrams at a dealer like www.arcolawn.com. You can purchase the service manual at a dealer and it will show you how to hook it up.
The throttle linkage hooks up to the throttle shaft closest to the engine. the governor spring attaches the governor arm to the throttle linkage.
The choke cable attaches to the shaft farthest from the engine. I hope this helps.
PS your engine has two factory service bulletins on it.
Joe

It sounds like the fuel mixture is running very Lean..There are usually two adjusting screw screws on the carburettor that control the mixture. A Larger one is for the Main Jet and a smaller one for the Idle Jet. There is also an adjusting screw on the throttle butterfly to control the idle speed.
To adjust setup, start with at least a half tank of fuel, and have engine at operating tempurature (That is warm but not overly Hot). As a starting point, loosen (anticlockwise) Main Jet screw about half a turn, to richen mixture,so that engine will run without choke. Run engine at full speed and adjust main jet for highest smooth speed without engine missing due to mixture being too lean or rich.
Allow engine to idle and the adjust Idle Jet Screw for smoothest idle. Idle Speed screw may have to be adjusted if idle speed is too high/low.
Sequence above may have to be repeated to get best running. If engine hesitates sometime when sudden load is applied but then picks up, try adjusting Main Jet by 1/8 to 1/4 turn richer until it handles the load without faltering.

could be air cleaner clogged and/or crankcase ventilation
breather or tube to air cleaner frame work clogged

Check the choke, if that doesn't work the old gas may have left residue that is plugging your ports.

same problem, was told it was the jets, are your symptoms as follows
runs at low throttle, will only run at full throttle if fully choked
dies if choke is relieved

You are not getting enough fuel.... by choking it you are enriching the mixture with less air , more fuel.Some where in the fuel system or carbureator something is still plugged.Or the mixture screw is too far in.

I THINK THE CARBY NEEDS A KIT AND SOME ADJUSTMENT

sounds like you sucked up dirt in the carb needs to be taken off and cleaned

SOUNDS LIKE A FUEL PROBLEM OR DIRT WHAT OTHER SYMPTONS DOES IT HAVE