Honda CRF450R 2006, Owner'S Manual

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Piston/Piston Rings/Piston Pin
68
Servicing Your Honda
Cylinder Removal
1. Remove the cylinder bolt (1) and cylinder (2).
Do not let the cam chain fall into the crankcase.
Do not pry on or strike the cylinder.
NOTICE
(1) cylinder bolt (2) cylinder
2. Remove the A dowel pins (3), B dowel pin (4)
and cylinder gasket (5).
Do not let the dowel pins fall into the crankcase.
NOTICE
(3) A dowel pins (5) cylinder gasket
(4) B dowel pin
Piston Removal
1. Place clean shop towels in the crankcase to
keep the piston pin clips, or other parts, from
falling into the crankcase.
2. Remove the piston pin clips (1) using a pair of
needle-nose pliers.
3. Press the piston pin (2) out of the piston (3),
and remove the piston.
Under racing conditions, the piston and rings
should be replaced after 15.0 hours of running.
Replace the piston pin after 30.0 hours of running.
4. Spread each piston ring (4) and remove by
lifting it up at a point just opposite the gap.
Do not damage the piston ring by spreading the
ends too far.
NOTICE
(2)
(1)
(5)
(4)
(3)
(3)
(2)
(1)
(1) piston pin clip (3) piston
(2) piston pin
(4)
(4) piston ring