Cylinder Head Assembly - BRP BOMBARDIER DS250 2006 Shop Manual

VALVE GUIDE INNER DIAMETER
DESCRIPTION
New
Service limit
If part does not meet requirements, replace cylin-
der head.
NOTE: Whenever a valve guide is replaced, it
must be properly reamed.
Timing Chain
Check timing chain sprocket condition. Mesh
chain in sprocket and check for excessive radial
play.
Check chain condition for wear and the condition
of the chain segments.
1. Timing chain
2. Timing chain segments
3. Timing chain bending
If sprocket is worn or timing chain is excessively
worn or damaged, replace them as a set: crank-
shaft, camshaft gear and chain. Refer to CRANK-
SHAFT AND CRANKCASE for procedures.
Chain Tensioner
Check tensioner notches for damage.
Install spring and screw. Tensioner pusher should
go out.
Try to push in pusher. It must not go in. Other-
wise, replace it.
vmr2006-073
INTAKE
5.000 - 5.012 mm
(.1968 - .1973 in)
5.030 mm (.1980 in)
Subsection 08 (CYLINDER HEAD)
vmr2006-073-026_a

CYLINDER HEAD ASSEMBLY

Assembly is essentially the reverse procedure of
disassembly. However, pay attention to the fol-
lowing.
Cylinder Head
Install new valve stem seals every time valves are
removed.
When installing new valves, apply some lapping
compound to valve face and work valve on its seat
with a lapping tool. Ensure to properly clean cylin-
der head and valve when done.
vmr2006-073-029
Position inner spring with its tightest coils against
cylinder head.
Position painted area of outer spring against valve
spring retainer.
Section 03 ENGINE
79