2011 Arctic Cat 150 ATV Service Manual, Page 53Get this manual
INSTALLING
1If removed, connect the vent hose onto the carburetor2If the throttle valve was removed, install the jet needle (C), needle holder (B), and spring (A) into the throttle valve (D) making sure the E-clip on the needle is in the fourth groove (counting from the top); then connect it to the throttle cable
3Slide the throttle valve into the carburetor making sure the alignment pin in the carburetor engages in the throttle valve groove; then secure the assembly into the carburetor with the cap and tighten securely