Yamaha Fz1n Service Manual

CRANKSHAFT
5-83
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2. Select: Crankshaft journal bearings (J1–J5)
NOTE:
 The numbers “A” stamped into the crank-shaft web and the numbers “1” stamped into 
the lower crankcase are used to determine 
the replacement crankshaft journal bearing 
sizes.
 “J1–J5” refer to the bearings shown in the  crankshaft illustration.
 If “J1–J5” are the same, use the same size 
for all of the bearings.
 If the size is the same for all “J
1 to J5” one 
digit for that size is indicated....

CRANKSHAFT
5-84
NOTE:
 Align the projections “a” on the crankshaft journal upper bearings with the notches “b” in 
the upper crankcase.
 Be sure to install each crankshaft journal 
upper bearing in its original place.
3. Install:  Crankshaft
4. Install:  Crankcase (lower)Refer to CRANKCASE on page 5-66.
5. Install: Pin
 Pickup rotor “1”
 Drive sprocket “2”
Drive sprocket bolt60 Nm (6.0 m·kg, 43 ft·lb) 

TRANSMISSION
5-85
EAS26240
TRANSMISSION
Removing the transmission, shift drum assembly, and shift forks
Order Job/Parts to remove Q’ty RemarksCrankcase lower Separate.
Refer to CRANKCASE on page 5-
66
.
1 Drive axle assembly 1
2 Circlip 1
3 Oil seal 1
4 Bearing 1
5 Washer 1
6 Shift fork guide bar retainer 2
7Spring 2
8 Shift fork guide bar 2
9 Shift fork “L” 1
10 Shift fork “R” 1
11 Shift drum assembly 1
12 Shift fork “C” 1
13 Main axle retainer 1 

TRANSMISSION
5-86
14 Main axle assembly 1
15 Oil pipe 1
16 O-ring 2
17 Oil baffle plate 1For installation, reverse the removal 
procedure.
Removing the transmission, shift drum assembly, and shift forks
Order Job/Parts to remove Q’ty Remarks 

TRANSMISSION
5-87
Disassembling the main axle assenbly
Order Job/Parts to remove Q’ty Remarks1 2nd pinion gear 1
2 Toothed lock washer 1
3 Toothed lock washer retainer 1
4 6th pinion gear 1
5Collar 1
6 Washer 1
7 Circlip 1
8 3rd pinion gear 1
9 Circlip 1
10 Washer 1
11 5th pinion gear 1
12 Collar 1
13 Main axle 1
14 Bearing housing 1
15 Bearing 1 For assembly, reverse the disassem-
bly procedure. 

TRANSMISSION
5-88
Disassembling the drive axle assenbly
Order Job/Parts to remove Q’ty Remarks1 Washer 1
2 1st wheel gear 1
3Collar 1
4 5th wheel gear 1
5 Circlip 1
6 Washer 1
7 3rd wheel gear 1
8Collar 1
9 Toothed lock washer 1
10 Toothed lock washer retainer 1
11 4th wheel gear 1
12 Collar 1
13 Washer 1
14 Circlip 1
15 6th wheel gear 1
16 Circlip 1
17 Washer 1
18 Collar 1
19 2nd wheel gear 1
20 Collar 1 

TRANSMISSION
5-89
21 Oil seal 1
22 Bearing 1
23 Drive axle 1For assembly, reverse the disassem-
bly procedure.
Disassembling the drive axle assenbly
Order Job/Parts to remove Q’ty Remarks 

TRANSMISSION
5-90
EAS26250
REMOVING THE TRANSMISSION
1. Remove: Drive axle asseembly “1”
 Shift drum retainers “2”
 Shift fork guide bars
 Shift fork “L” and “R”
 Shift drum assembly
 Shift fork “C”
2. Remove:  Bearing housing “1”
 Main axle assembly “2”
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a. Insert two bolts “3” of the proper size, as  shown in the illustration, into the main axle 
assembly bearing housing.
b. Tighten the bolts until they contact the  crankcase surface.
c. Continue tightening the...

TRANSMISSION
5-91
3. Check: Shift fork movement(along the shift fork guide bar)
Rough movement  → Replace the shift 
forks and shift fork guide bar as a set.
EAS26270
CHECKING THE SHIFT DRUM ASSEMBLY
1. Check:  Shift drum grooves “1”
Damage/scratches/wear  → Replace the 
shift drum assembly.
 Shift drum segment “2” Damage/wear  → Replace the shift drum 
assembly.
 Shift drum bearing “3” Damage/pitting  → Replace the shift drum 
assembly.
EAS26280
CHECKING THE TRANSMISSION
1. Measure:  Main axle...

TRANSMISSION
5-92
ET2D1022
INSTALLING THE TRANSMISSION
1. Install: Bearing “1”
NOTE:
Make the seal side of bearing face to the out-
side and install it close to the right end face of 
the crankcase.
 Oil pipe “2”
2. Install:  Main axle assembly “1”
 Bearing housing “2”
 Shift fork “C”
 Shift drum assembly
 Shift fork guide bar
 Shift fork guide bar retainer
NOTE:
 The embossed marks on the shift forks should face towards the right side of the 
engine and be in the following sequence: “R”, 
“C”,...