Checking The Autochoke Unit - Yamaha YB50 Service Manual

CARBURETOR
EAS00503

CHECKING THE AUTOCHOKE UNIT

NOTE:
When checking the autochoke unit, the
ambient temperature must be lower than 45°C
(113°F).
1. Remove:
• carburetor
2. Check:
• autochoke unit
a. Connect a 3.3 mm hose
passage and blow into the hose.
NOTE:
When the starter plunger is open, air should
come out of the other side of the starter air
passage.
Starter plunger
opens
Starter plunger
closes
3. Check:
• autochoke unit
a. Connect the autochoke unit leads to a
12.0 V battery for five minutes.
Positive batter lead
Negtive battery lead
b. Connect a 3.3 mm hose
passage and blow into the hose.
Starter plunger
opens
Starter plunger
closes
5-6
CARB
to the starter air
Perform step (3)
Replace the auto-
choke unit.
yellow/red
black
to the starter air
Replace the auto-
choke unit.
Autochoke is OK.