Assembly And Installation - Yamaha YZ250F Fahrer- Und Wartungshandbuch

CAMSHAFTS
Decompression system
1. Check:
Decompression system
G
Checking steps:
Check that the decompression mecha-
G
nism cam 1 moves smoothly.
Check that the decompression mechanism
G
cam lever pin 2 projects from the camshaft.
Timing chain tensioner
1. Check:
While pressing the tensioner rod lightly
G
with fingers, use a thin screwdriver 1
and wind the tensioner rod up fully
clockwise.
When releasing the screwdriver by
G
pressing lightly with fingers, make sure
that the tensioner rod will come out
smoothly.
If not, replace the tensioner assembly.
G

ASSEMBLY AND INSTALLATION

Camshaft
1. Install:
Exhaust camshaft 1
G
Intake camshaft 2
G
Installation steps:
Turn the crankshaft counterclockwise with
G
a wrench.
NOTE:
Apply the molybdenum disulfide oil on the
G
camshafts.
Apply the engine oil on the decompression
G
system.
Squeezing
G
allows the crankshaft to be turned easily.
Align the T.D.C. mark a on the rotor with the
G
align mark b on the crankcase cover when
piston is at T.D.C. on compression stroke.
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ENG
the decompression lever