GENUINE Blur 150, Service Manual

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AUTO-ENRICHENER (AUTO-CHOKE) SYSTEM
The automatic enrichener (automatic choke) device consists of the PTC heater A, the
thermo-wax B and the plunger/needle . When the thermo-wax B is cold, the plunger/needle
moves upward, Fuel is drawn into the enrichener circuit from the float chamber .
Enrichener jet meters this fuel, which then flows into fuel pipe and mixes with the air
coming From the upper part of the float chamber . The mixture, rich in fuel content, reaches upper
part of The fuel pipe and mixes again with the air coming through a passage extending from main
bore .
The two succesive mixings of fuel with air are such that proper fuel/air mixture for starting is
produced when the mixture is sprayed out through outlet port into the main bore.
NOTE:
An enrichener is operated almost the same way as a choke.
When the engine is cold:
The automatic enrichener passage is always open as the thermo-wax remains atomospheric temperature.
When the engine is started:
According to the PTC heater temperature, the thermo-wax gradually expands and closes enrichener
passage by the needle of the plunger.