Impeller Shaft Removal; Oil Seal Removal, Check And Installation; Oil Delivery Pipe Check; Impeller Shaft Check - Yamaha 2011 YZ250F Owner's Service Manual

REMOVING THE IMPELLER
SHAFT
1. Remove:
• Impeller "1"
• Washer "2"
• Impeller shaft "3"
Hold the impeller shaft on its width
across the flats "a" with spanners,
etc. and remove the impeller.
REMOVING THE OIL SEAL
It is not necessary to disassemble the
water pump, unless there is an abnor-
mality such as excessive change in
coolant level, discoloration of coolant,
or milky transmission oil.
1. Remove:
• Bearing "1"
2. Remove:
• Oil seal "1"
OIL FILTER ELEMENT AND WATER PUMP
CHECKING THE OIL DELIVERY
PIPE
1. Inspect:
• Oil delivery pipe "1"
Bend/damage → Replace.
Clogged → Blow.
CHECKING THE IMPELLER SHAFT
1. Inspect:
• Impeller shaft "1"
Bend/wear/damage → Replace.
Fur deposits → Clean.
CHECKING THE IMPELLER SHAFT
GEAR
1. Inspect:
• Gear teeth "a"
Wear/damage → Replace.
CHECKING THE BEARING
1. Inspect:
• Bearing
Rotate inner race with a finger.
Rough spot/seizure → Replace.
4-35
CHECKING THE OIL SEAL
1. Inspect:
• Oil seal "1"
Wear/damage → Replace.
INSTALLING THE OIL SEAL
1. Install:
• Oil seal "1"
• Apply the lithium soap base grease
on the oil seal lip.
• Install the oil seal with its manufac-
ture's marks or numbers facing the
right crankcase cover "2".
2. Install:
• Bearing "1"
Install the bearing by pressing its out-
er race parallel.