Honda CRF450X 2020 Owner's Manual & Competition Handbook page 102

Piston/Piston Rings/Piston Pin
Piston Installation
1. Place clean shop towels (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
grease containing more than 3% molybdenum
disulfide additive Moly Paste 77) to the
connecting rod small end (2) inner surface.
(2)
(1) shop towels
(2) connecting rod small end
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Servicing Your Honda
3. Install the piston (3) with the "IN" mark (4)
and/or the large valve recesses (5) facing the
intake side of the engine.
(3)
(1)
(3) piston
(4) "IN" mark
Apply molybdenum disulfide oil (a mixture of
1/2 engine oil and 1/2 molybdenum disulfide
grease containing more than 3% molybdenum
disulfide additive Moly Paste 77) to the piston
pin (6) outer surface. Apply engine oil to the
piston outer surface and piston pin hole inner
surface. Install the piston pin and new piston
pin clips (7).
NOTICE
Be careful not to damage or shock the piston pin.
Use new pin clips. Never reuse old clips.
Do not let the clips fall into the crankcase.
Do not align the piston pin clip end gap with the
piston cutout (8).
(4)
(6) piston pin
(7) piston pin clips (new)
(5)
(5) large valve recesses
(7)
(7)
(6)
(8) piston cutout
(8)
(7)