Installing The Piston And Cylinder - Yamaha YZ250X 2022 Owner's Service Manual

TIP
First tighten the power valve link lever bolt, and
then tighten the pulley bolts.
6. Check:
• Power valve 1 smooth movement
Unsmooth movement  Repair or replace.
7. Install:
• O-ring "1"
New
• Side holder "2"
• Side holder screw "3"
Side holder screw
4.0 N·m (0.40 kgf·m, 3.0 lb·ft)
• YPVS breather hose "4"
TIP
• Apply the lithium-soap-based grease on the O-
rings.
• Install the side holder with its projection "a" fac-
ing upward.
1
3
a
2
3
CYLINDER HEAD, CYLINDER AND PISTON
8. Install:
• Gasket (power valve cover) "1"
• Power valve cover "2"
• Power valve cover screw "3"
TIP
• Install the gasket with its cut "a" facing down-
ward and the seal print side toward the power
valve cover.
• Install the power valve cover so that the arrow
mark "b" faces upward.
EAM30554

INSTALLING THE PISTON AND CYLINDER

1. Install:
• Piston ring "1"
TIP
• Take care not to scratch the piston or damage
the piston ring.
• Align the piston ring gap with the pin "2".
• After installing the piston ring, check the
smooth movement of it.
1
3
2
a
3
4
5-12
Power valve cover screw
4.0 N·m (0.40 kgf·m, 3.0 lb·ft)
New