2013 YAMAHA YFZ450 Owners Manual

Page 89 of 154

YAMAHA YFZ450 2013  Owners Manual 8-7
8
14*Chassis fasteners  Make sure that all nuts, bolts, and screws are 
properly tightened. √√√√√
15 *Shock absorber as-
semblies  Check operation and correct if necessary.
 Check for oi

Page 90 of 154

YAMAHA YFZ450 2013  Owners Manual 8-8
8
EBU23071TIP●Some maintenance items need more frequent service if you are riding in unusually wet, dusty, sandy or
muddy areas, or at full-throttle.●Hydraulic brake service
 Regularly check a

Page 91 of 154

YAMAHA YFZ450 2013  Owners Manual 8-9
8
EBU23080Removing and installing the panel The panel shown needs to be removed to perform
some of the maintenance jobs described in this
chapter. Refer to this section each time the panel
needs t

Page 92 of 154

YAMAHA YFZ450 2013  Owners Manual 8-10
8To install the panel
1. Place the panel in the original position, and
then install the quick fastener screw and the
bolts. 2. Install the seat.
EBU23245Checking the spark plug The spark plug is

Page 93 of 154

YAMAHA YFZ450 2013  Owners Manual 8-11
8
To remove the spark plug
1. Remove the seat. (See page 4-12.)
2. Remove the bolts and the quick fastener screws shown.
3. Remove the fuel tank cap by turning it coun- terclockwise.  WARNING! Ne

Page 94 of 154

YAMAHA YFZ450 2013  Owners Manual 8-12
87. Remove the spark plug cap. 
NOTICE: Do not
use any tools to remove or install the
spark plug cap, otherwise the ignition coil
coupler may be damaged. The spark plug
cap may be difficult to re

Page 95 of 154

YAMAHA YFZ450 2013  Owners Manual 8-13
8
To check the spark plug
1. Check that the porcelain insulator around the center electrode of the spark plug is a medi-
um-to-light tan (the ideal color when the ATV
is ridden normally).
TIPIf t

Page 96 of 154

YAMAHA YFZ450 2013  Owners Manual 8-14
8To install the spark plug
1. Clean the surface of the spark plug gasket and its mating surface, and then wipe off any
grime from the spark plug threads.
2. Install the spark plug with the spark