Engine Break-In - Yamaha YZ85 2013 Owner's Manual

OPERATION AND IMPORTANT RIDING POINTS

Engine break-in

WARNING
Failure to properly maintain the vehi-
cle or performing maintenance ac-
tivities incorrectly may increase
your risk of injury or death during
service or while using the vehicle. If
you are not familiar with vehicle ser-
vice, have a Yamaha dealer perform
service.
1. Before starting the engine, fill the
fuel tank with a break-in oil-fuel
mixture as follows.
6
Recommended 2-stroke engine oil:
See page 9-1.
Mixing ratio (gasoline to oil):
15:1
2. Start and warm up the engine.
Check the operation of the con-
trols and the engine stop button.
(See page 4-1.)
3. Operate the motorcycle in the
lower gears at moderate throttle
openings for five to eight minutes.
Stop the engine and check the
spark plug condition (see page
EAU41504
7-8); it will show a rich condition
EWA10322
during break-in.
4. Allow the engine to cool. Restart
the engine and operate the motor-
cycle as in the step above for five
minutes. Then, very briefly shift to
the higher gears and check the
full-throttle response. Stop the en-
gine and check the spark plug.
5. After again allowing the engine to
cool, restart and run the motorcy-
cle for five more minutes. Full
throttle and the higher gears may
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 4-3.)
8. Start the engine and check the op-
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
6-3
eration of the motorcycle through-
out its entire operating range.
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.
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:
ECA15561