Periodic maintenance and adjustment
6-15
6
EAU21403
Valve clearance
The valves are an important engine
component, and since valve clearance
changes with use, they must be
checked and adjusted at the intervals
specified in the periodic maintenance
chart. Unadjusted valves can result in
improper air-fuel mixture, engine
noise, and eventually engine damage.
To prevent this from occurring, have
your Yamaha dealer check and adjust
the valve clearance at regular intervals.
TIP
This service must be performed when
the engine is cold.
EAU64410
Tires
Tires are the only contact between the
vehicle and the road. Safety in all con-
ditions of riding depends on a relatively
small area of road contact. Therefore, it
is essential to maintain the tires in good
condition at all times and replace them
at the appropriate time with the speci-
fied tires.
Tire air pressure
The tire air pressure should be
checked and, if necessary, adjusted
before each ride.
WARNING
EWA10504
Operation of this vehicle with im-
proper tire pressure may cause se-
vere injury or death from loss of
control.
t
The tire air pressure must be
checked and adjusted on cold
tires (i.e., when the temperature
of the tires equals the ambient
temperature).
t
The tire air pressure must be
adjusted in accordance with the
riding speed and with the total
weight of rider, passenger, car-
go, and accessories approved
for this model.
WARNING
EWA10512
Never overload your vehicle. Opera-
tion of an overloaded vehicle could
cause an accident.
Tire air pressure (measured on cold
tires):
1 person:
Front:
225 kPa (2.25 kgf/cm², 33 psi)
Rear:
250 kPa (2.50 kgf/cm², 36 psi)
2 persons:
Front:
225 kPa (2.25 kgf/cm², 33 psi)
Rear:
250 kPa (2.50 kgf/cm², 36 psi)
Maximum load*:
172 kg (379 lb)
* Total weight of rider, passenger, car-
go and accessories
Summary of Contents for MTN690-A 2019
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