Cobra Y173V, Service Manual

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3. MAINTENANCE
16
THROTTLE VALVE
GOVERNOR SUPPORT
GOVERNOR ARM
NUT M6
Clearance too big: Intake and exhaust valve opening delay will shorten the intake and
exhaust time, lower the opening height of the valve and change normal distributing phase to
result in power lowering from the intake lack and exhaust uncompleted. Furthermore, also
make vale train parts knock increasing and wearing quickly.
Clearance too small: After running, engine parts will be heated to expand and push the valve
open, which will make the engine not closing tight and result in leaking, power lowering,
serious carbon deposit or burn on the valve surface, even valve impacting the piston.
3-7
Governor
Governor
adjustment
a) Remove the air cleaner.
b) Loosen the nut (M6). Be sure that
the carburetor throttle valve is
fully open.
c) Rotate the governor support shaft
fully to the right (governor fully
closed position), and tighten the
nut.
TORQUE VALUE: 10-12N.m
d) Check to see that the governor support and throttle valve move freely.
e) Check the maximum engine speed
Maximum Speed Adjustment
a) Start the engine and allow it to warm up to normal operating temperature.
b) If the maximum speed not conforming to specified value, adjust the adjusting bolt
M4
×
30.
Engine maximum speed
：
2850±100rpm
Speed too big Turn the bolt counterclockwise.
Speed too small Turn the bolt clockwise