Adjust the engine idle speed periodically on the engine at normal operating temperature.
To adjust the idle speed:

Engine oil and filter change
Throtile cable playCylinder head cover related parts
inspection
Refer to “engine top side disassembly” .
Refer to “engine top side assembly” .
Refer to “cylinder head cover disassembly and assembly” .
Cylinder head cover
Clean and check the gasket grooves “a” and pair reed
valve mating surfaces “b” of the cylinder head cover.
If there is anything unu ...
Battery
Battery connection in reverse polarity is strictly
prohibited. Such a wrong connection will damage the
components of the fi system instantly when reverse
power is applied.
Removing any battery terminal of a running engine is
strictly prohibited. The moment such removal is made,
...
DTC “c28” (p1655): secondary throttle
valve actuator (stva) malfunction
Detected condition and possible cause
Detected condition
Possible cause
The operation voltage does not reach the stva.
Ecm does not receive communication signal from the
stva. Stva can not operate properly or its motor locked
Stva malfunction.
...