Upper Crankcase

UPPER CRANKCASE

 

1 Crankshaft bearing 
2 Drive chain guide 
3 Starter idle gear 
4 A.C.G. drive chain
5  Oil seal
6  Starter clutch assembly
7 Main axle assembly
8 A.C.G. shaft

9 O-ring

10 Oil spray nozzle
11 Housing
12 Cam chain guide

 

CONNECTING ROD BEARING SELECTION: 
CONNECTING ROD BEARING = 
CONNECTING ROD NO. - CRANKSHAFT NO.

CALCULATED NO.

COLOR CODE

1

BLUE

2

BLACK

3

BROWN

4

GREEN

1. Install:
• Crankshaft bearings 1
• Drive chain guide 2
• Starter idle gear 3

Drive Chain Guide: 8 Nm (0.8 m-kg, 5.8 ft-lb) 
Starter Idle Gear: 8 Nm (0.8 m-kg, 5.8 ft-lb)

2.  Apply engine oil to the bearings.

3.  Place the cam chain 1 , drive chain 2 , and oil seal 3 onto the crankshaft.

4.  Install the crankshaft (onto the upper crankcase)

NOTE: 
• Insert the oil seal flange completely into the crankcase positioning groove. 
•Be careful not to damage the oil seal duringinstallation.

• Blind plug 4
• Dowel pins 5

5. Place the drive chain on the starter clutch assembly.

6. Install
• Starter clutch assembly 1 onto the upper crankcase
• A.C.G. shaft

7. Install:
• Oil spray nozzle 1 with new O-ring 2
• Housing with new oil seal 3

NOTE:
Lightly apply grease to the oil seal lips.

Housing Bolt: 10 Nm (1.0 m-kg, 7.2 ft-lb) LOCTITE®

8.  Install:
• O-ring (New) 1
• Dowel pins 2
• Half clips 3
• Main axle assembly 4
• Bearing 5
• Middle drive shaft assembly 6

9.  Position the bearing pin (left bearing) as shown 7.

CRANKCASE ASSEMBLY

1.  Attach a length of wire to the cam chain.

2.  Apply Yamaha bond No. 1215 (908 8 5505).

NOTE:
DO NOT ALLOW any sealant to come in contact with the oil galley O-ring, or crankshaft bearings. Do not apply sealant to within 2-3 mm (0.08-0.12 in) of the bearings.

3. Install the lower crankcase onto the upper crankcase.

• Be sure the shift fork (No. 1 ) 1 engages the groove 2 in the 2nd pinion gear on the main axle.
• Insert the oil seal and blind seal flanges completely into the crankcase positioning grooves.
• Be careful not to damage the seals during installation.

4.  Install:
• Bolts 
• Washers
• Clamps
• Battery negative lead

5.  Tighten:
• Crankcase bolts

Crankcase: 
6 mm bolt: 12 Nm (1.2m-kg, 8.7ft-lb) 
8 mm bolt: 24 Nm(2.4m-kg, 17 ft-lb)

NOTE:
The embossed numbers in the crankcase designate the crankcase tightening sequence.

LOWER CRANKCASE

UPPER CRANKCASE