Yamaha YZ85 2017 Owner's Manual page 34

Operation and important riding points
be used, but sustained full-throttle
operation should be avoided.
Stop the engine and check the
spark plug again.
6. Allow the engine to cool, remove
the cylinder head and cylinder,
and inspect the piston and cylin-
der. Remove any high spots on
the piston with #600-grit wet
sandpaper. Clean all components
and carefully reassemble the cyl-
inder head and cylinder.
7. Drain the break-in oil-fuel mixture
from the fuel tank and refill with
the specified mix. (See page 4-4.)
8. Start the engine and check the op-
eration of the motorcycle through-
out its entire operating range.
6
Stop the engine and check the
spark plug condition. Restart the
motorcycle and ride it for about 10
to 15 more minutes. The motorcy-
cle will now be ready to ride nor-
mally.
After the engine break-in period, thor-
oughly check the motorcycle for loose
parts, oil leakage and any other prob-
lems. Be sure to inspect and make ad-
justments thoroughly, especially cable
and drive chain slack and loose
spokes. In addition, check all fittings
and fasteners for looseness, and tight-
en if necessary.
NOTICE
 When any of the following parts
have been replaced, they must
be broken in.
Cylinder or crankshaft:
About one hour of break-in op-
eration is necessary.
Piston, rings or transmission
gears:
These parts require about 30
minutes of break-in operation at
half-throttle or less. Observe the
condition of the engine carefully
during operation.
 If any engine trouble should oc-
cur during the engine break-in
period, immediately have a
Yamaha dealer check the vehi-
cle.
ECA15561
6-4