Starting And Warming Up A Cold; Engine - Yamaha YZ85 2021 Owner's Manual

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 normal oil-fuel mixture. (See
page 4-3.)
8. Start the engine and check its
power delivery and throttle re-
sponse throughout all gear rang-
es. Stop the engine and check the
spark plug condition. It should be-
gin to lighten in color.
9. Restart the motorcycle and ride it
for about 10 to 15 more minutes.
Stop the engine and check the
spark plug condition. (See page
7-7.)
10. Lastly, thoroughly check the mo-
torcycle for loose parts, oil leak-
age and any other problems.
Check all fittings and fasteners
and tighten as necessary.
Operation and important riding points
TIP
Be sure to inspect and make adjust-
ments thoroughly. In particular, check
control cable slack, drive chain slack
and for loose spokes.
Notes on engine overhauls
If the following parts have been re-
placed, they must be broken in as fol-
lows.
 Piston,
rings or transmission
gears: 30 minutes of break-in op-
eration at half-throttle or less.
 Cylinder or crankshaft: 60 minutes
of break-in operation is necessary.
TIP
Observe the condition of the engine
carefully during break-in operation.
NOTICE
If any engine trouble should occur
during the engine break-in period,
immediately have a Yamaha dealer
check the vehicle.
6-2
Starting and warming up a
cold engine
1. Turn the fuel cock lever to "ON".
2. Shift the transmission into the
neutral position.
3. Turn the starter (choke) on and
completely close the throttle. (See
page 4-7.)
4. Start the engine by pushing the
kickstarter lever down.
5. When the engine is warm, turn the
starter (choke) off.
TIP
The engine is warm when it responds
quickly to the throttle with the starter
(choke) turned off.
NOTICE
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For maximum engine life, never ac-
celerate hard when the engine is
cold!
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6
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