Honda CRF250R 2005 Owner's Manual page 69

Cylinder Removal
1. Remove the cylinder bolt (1) and cylinder (2).
NOTICE
Do not let the cam chain fall into the crankcase.
Do not pry on or strike the cylinder.
(1)
(1) cylinder bolt
(2) cylinder
2. Remove the dowel pins (3) and cylinder
gasket (4).
NOTICE
Do not let the dowel pins fall into the crankcase.
(2)
(3) dowel pins
(4) cylinder gasket
Piston/Piston Rings/Piston 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),
(3)
and remove the piston.
NOTICE
Do not damage the piston.
Always support the piston when pressing out the pin.
Do not let the clips fall into the crankcase.
Under racing conditions, the piston and rings
(4)
should be replaced after 15.0 hours of running.
Replace the piston pin after 30.0 hours of running.
(3)
(1) piston pin clip
(2) piston pin
4. Spread each piston rings (4) and remove by
lifting it up at a point just opposite the gap.
NOTICE
Do not damage the piston ring by spreading the
ends too far.
(4)
(2) (1)
(3) piston
(4) piston rings
65
Servicing Your Honda