The plunger spring goes small end toward the plunger.

Reset the idle screw to 1.5 turns open. Reset the reg screw to flush with the casting. Start the engine at just above idle and let it run for 30 seconds. Go to full throttle and set the high end. The needle should be open about 2 turns to start and should be about 1.5 turns open when set correctly. Go back to idle for 15 seconds and note which way the engine wants to go, lean or rich and adjust the idle accordingly. Then advance the throttle and note the transition, too lean open the reg screw 1/4 turn at a time to richen. If too rich go in 1/4 at a time.

If none of this works, box it up and send it to our service dept. because it need help.

Dave