Honda CRF450R 2009 Owner's Manual & Competition Handbook page 84

Piston/Piston Rings/Piston Pin
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)
(3) piston (5) large valve recesses
(4) "IN" mark
4. Apply engine oil 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
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).
78
Servicing Your Honda
(4)
(7)
(6) piston pin
(7) piston pin clips
(5)
(8)
(6)
(7)
1. Clean off any gasket material from the gasket
(6)
2. Remove the shop towels. Do not let any
3. Install a new cylinder gasket (1) and dowel
(8) piston cutout
Do not let the dowel pins fall into the crankcase.
(1) cylinder gasket
Cylinder Installation
surface of the crankcase, being careful not to
let any material fall into the crankcase.
Be careful not to remove any metal from the
gasket surface.
gasket debris fall into the crankcase.
pins (2).
NOTICE
(2)
(1)
(2) dowel pins