[springforward1]

I have a Kohler 26hp v-twin Pro w/nikki carb. It runs smoothly at half throttle w/ about 30% choke not engaged. Dies instantly when engaged. I have drained,flushed & refulled. Rebuilt carb & accelerator pump & replaced fuel pump. Any advice would be greatly appreciated.

 

[Bill Kapaun]

Why would you engage the choke if it's running smoothly?

 

[springforward1]

would not run unless the choke was pulled out.

 

[tomw0]

One would be led to think that you are not getting enough fuel to or through the carburetor. Feed the float bowl via a gravity tank, and if that works, your pump or lines are dysfunctional. When running on a gravity feed, the pump and fuel tank should be pumping the tank empty at a pretty quick rate, so have a catch-can ready just in case the problem is within the carb.
Doing that will at least point to the carb or fuel delivery system.
tom