Honda CRF250R 2018 Owner's Manual page 88

Piston Ring Installation
1. Remove the carbon deposits from the piston
head and piston ring grooves.
NOTICE
Do not damage the piston when removing the
carbon deposit.
2. Apply engine oil to each piston ring whole
surface.
3. Install the spacer (1) first, then install the side
rails (2) to the piston (3).
4. Install the top ring (4) to the piston with "T"
mark (5) side facing up.
NOTICE
Do not damage the piston ring by spreading the
ends too far.
Do not damage the piston during piston ring
installation.
5. After installing the piston rings they should
rotate freely, without sticking.
Space the ring end gaps 180 degrees apart
between top ring and upper side rail.
Space the ring end gaps 90 degrees apart
between upper side rail, spacer and lower side
rail.
(5)
(1) spacer (4) top ring
(2) side rails (5) "T" mark
(3) piston
Piston/Piston Rings/Piston Pin
Piston Installation
1. Place a clean shop towel (1) over the crankcase
opening to keep the piston pin clips from
falling into the crankcase.
2. Apply molybdenum disulfide oil (a mixture of
1/2 engine oil and 1/2 molybdenum disulfide
(4)
grease containing more than 3% molybdenum
disulfide additive Moly Paste 77) to the
(2)
connecting rod small end (2) inner surface.
(1)
(2)
(2)
(4)
(2)
(1)
(1) shop towel
(2)
(2) connecting rod small end
(3)
(1)
(cont'd)
83
Servicing Your Honda