Suspension general diagnosisDTC “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.
...
Modification
Modification of the motorcycle, or
removal of original equipment
may render the vehicle unsafe or
illegal. Obey all applicable equipment
regulations in your area.
The frame of this motorcycle is
made of an aluminum alloy.
Therefore, never make any modifications
such as drilling or weldin ...
Valve seat repair
The valve seats (1) for both the intake and exhaust
valves are machined to three different angles. The seat
contact surface is cut at 45°.
Intake valve
Exhaust valve
Caution
the valve seat contact area must be
inspected after e ...