variable Air induction on a carburetor?
 

Today I picked up a 13b series 4 that has been converted to carburetor. upon assembly I found that there are some hooks on my air intake that link onto the air induction tubes but there is no mechanism or linkage to control the tubes. my question is what controls the air induction on a carburetor conversion?
im new to rotary engines and new to this forum, any help/links would be much appreciated.
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