Repair manual

WM 80 Repair Carburetor Basics
wc_tx000522gb.fm 49
Start up
A rich fuel-to-air mixture is required at startup because of the lower
cranking speed (compared to running) which causes less air flow, and
the fact that the engine is usually cold. (A cold engine is not efficient at
vaporizing fuel because heat is required to vaporize liquid.)
The above two conditions can be overcome by closing the choke (a)
and opening the throttle (b) slightly. This creates a high vacuum within
the carburetor’s throat which causes all fuel nozzles to deliver fuel into
the intake air stream.
wc_gr005109
a
b