Yamaha SXV70ERG, Supplementary Service Manual

Page: 22 / 173

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YAMAHA POWER VALVE SYSTEM
(Y.P.V.S.) PRE-SEASON CHECKS
INSP
ADJ
Start the engine.
Remove the cover.
Check if there is any
freeplay on the Y.P.V.S.
cables.
Freeplay
Turn the pulley to remove
the freeplay.
With the engine running at idle
speed, check that there is freeplay
on the Y.P.V.S. cables.
No freeplay
* The valve maybe stuck in
the fully-opened position
and the servo motor maybe
fully closed.
Adjust the idle speed below 900
r / min.
* The valve fully opens below
1,000 r / min.
Are the warning light and
LCD lit?
No
No freeplay
Yes
S
If the valve is stuck, inspect it and then either remove any carbon or reassemble the valve, refer to the
“YAMAHA POWER VALVE SYSTEM (Y.P.V.S.)” in CHAPTER 5.
S
If the valve is not stuck, but the warning light and self-diagnosis warning indicator remains lit, refer to
the “SELF-DIAGNOSIS” in CHAPTER 8.
Freeplay
* There is freeplay because the
valve is either stuck in the
half-or fully-opened position.
Check that the warning light and
self-diagnosis warning indicator,
lights up.
The Y.P.V.S. is ok. Adjust the
idle speed to specification. Refer to “SELF-DIAGNOSIS” in
CHAPTER 8.
Does the warning light
and self-diagnosis
warning indicator blink
seven times in five
seconds?
Does not light up
Light up
* If the valve is stuck
in the fully-closed or
half-opened position,
the diagnosis function
may indicate a faulty
servo motor.
Replace the bulb of warning
light or the LCD.
Yes
No