Yamaha WR250F 2021 - Checking the Valve Lifters; Installing the Valves

VALVES AND VALVE SPRINGS
5-31
EAM30094
CHECKING THE VALVE LIFTERS
1. Check:
• Valve lifter
Damage/scratches  Replace the valve lift-
ers and cylinder head.
EAM30095
INSTALLING THE VALVES
1. Clean:
• Valve stem end
2. Lubricate:
• Valve stem “1”
• Valve stem seal “2”
3. Install:
• Spring seat “1”
• Valve stem seal “2”
• Valve “3”
• Valve spring “4”
• Valve spring retainer “5”
(to the cylinder head)
TIP
• Make sure each valve is installed in its original
place.
• Install the valve springs with the larger pitch “a”
facing up.
4. Install:
• Valve cotter “1”
TIP
Install the valve cotters by compressing the
valve spring with the valve spring compressor
“2” and the valve spring compressor attachment
“3”.
Free length limit (intake)
34.94 mm (1.38 in)
Free length limit (exhaust)
33.82 mm (1.33 in)
Recommended lubricant
Molybdenum disulfide oil
b. Smaller pitch
Valve spring compressor
90890-04019
Valve spring compressor
YM-04019
Valve spring compressor attach-
ment
90890-04108
Valve spring compressor adapter
22 mm
YM-04108
New