BRP BOMBARDIER DS250 2006 Shop Manual page 97

Section 03 ENGINE
Subsection 08 (CYLINDER HEAD)
VALVE STEM DIAMETER
DESCRIPTION INTAKE
4.975 - 4.990 mm
New
(.1959 - .1965 in)
4.900 mm
Service limit
(.1929 in)
Check valve face and seat for burning or pittings.
Replace valve or cylinder head if damaged.
NOTE: Whenever a valve is replaced, it must be
properly faced.
TYPICAL
1. Valve seat
2. Valve stem
3. Valve face (contact surface to valve seat)
Measure valve face contact width.
NOTE: The location of contact area should be in
center of valve seat.
Measure valve seat width, using a caliper.
VALVE SEAT CONTACT WIDTH
Service limit
If valve seat contact width is too wide or has dark
spots, replace cylinder head.
78
EXHAUST
4.950 - 4.975 mm
(.1949 - .1959 in)
4.900 mm
(.1929 in)
1.60 mm (.063 in)
A. Valve face contact width
B. Valve seat contact width
Valve Guide
Clean valve guide with a 5 mm (.1968 in) reamer
to remove carbon deposits before measuring.
vmr2006-073-024_a
1. Reamer
Measure each valve guide inner diameter at 3 dif-
ferent places.
vmr2006-073-025
vmr2006-073