Position parts #21,#22,#20 just behind the #33-B (see photo below).

Install part # 34 and # 3 (see photo below).

Before tightening the screw (part #21), adjust part #33-B about the height
shown in photo below for great performance
Lowering the mixing tube (part 33 or 33-B) will decrease the light output (approx. 150 to 200-wattts), and can possibly decrease/increase the fuel odor.
The higher the mixing tube… the more light output(400 to 550 watts)and can possible decrease/increase fuel odor. However, in reference to the older generation lamps/lanterns, adjusting the tube too high, will decrease the light output. Unless you upgrade to BriteLyt parts.
SEE PHOTO FOR DEMONSTRATION OF STARTING POINT

Tighten screw #21 to hold #33-B in place. (Photo below)

Video Demonstration -(How to Put #33-B & #3-SS together)
BriteLyt NEWEST High-performance version of the Mixing Tube.
No butterfly adjustment screw.
High-performance part.
Provides better vapor flow.
Decreases, and in some cases, eliminates the odor of fuel, during lantern operation.
Increases light output, and helps prevent “yellowish” or “reddish” light from mantle.
Works on All 500CP and 350CP lanterns.(Petromax,BriteLyt,Hipolito,Aida, and Geniol)