Yamaha Fz6n Manual

							4-45
FRONT FORKCHAS
Order Job / Part Q’ty Remarks
1
2
3
4
5Removing the front fork legs
Front wheel
Front brake calipers
Front fender
Cap bolt
Upper bracket pinch bolt
Under bracket pinch bolt
Front fork leg1
1
1
1
1Remove the parts in the order listed.
Refer to “FRONT WHEEL AND BRAKE
DISCS”.
Refer to “FRONT AND REAR BRAKES”.
Loosen.
Loosen.
Loosen.
For installation, reverse the removal 
procedure.
30 Nm (3.0 m
kg, 22 ft
lb)
6 Nm (0.6 m
kg, 4.3 ft
lb)
30 Nm (3.0 m
kg, 22 ft
lb)
EAS00647
FRONT FORK
FRONT FORK LEGS 
						

							4-46
FRONT FORKCHAS
Order Job / Part Q’ty Remarks
Disassembling the front fork legs
Cap bolt
O-ring
Spacer
Washer
Front fork spring
Dust seal
Oil seal clip
Damper rod assembly bolt
Copper washer
Damper rod assembly
Oil seal
Washer1
1
1
1
1
1
1
1
1
1
1
1Disassemble the parts in the order listed.
The following the procedure applies to
both of the front fork legs.
NOTE:
1
3
2
4
5
6
7
8
9
10
11
12
24 Nm (2.4 m
kg, 17 ft
lb)
23 Nm (2.3 m
kg, 17 ft
lb)
EAS00648 
						

							4-47
FRONT FORKCHAS
Order Job / Part Q’ty Remarks
Inner tube
Outer tube bushing
Inner tube bushing
Oil flow stopper
Outer tube1
1
1
1
1
For assembly, reverse the disassembly
procedure.
13
14
15
16
17
24 Nm (2.4 m
kg, 17 ft
lb)
23 Nm (2.3 m
kg, 17 ft
lb) 
						

							4-48
FRONT FORKCHAS
WARNING
WARNING
NOTE:
EAS00649
REMOVING THE FRONT FORK LEGS
The following procedure applies to both of the
front fork legs.
1. Stand the motorcycle on a level surface.
Securely support the motorcycle so that
there is no danger of it falling over.
Place the motorcycle on a suitable stand so that
the front wheel is elevated.
2. Loosen:

upper bracket pinch bolt 
1

cap bolt 2

under bracket pinch bolt 3
Before loosening the upper and under
bracket pinch bolts, support the front fork
leg.
3. Remove:

front fork leg
EAS00652
DISASSEMBLING THE FRONT FORK LEGS
The following procedure applies to both of the
front fork legs.
1. Remove:

cap bolt

washer

spacer

fork spring
2. Drain:

fork oil
Stroke the inner tube several times while drain-
ing the fork oil. 
						

							4-49
FRONT FORKCHAS
CAUTION:
NOTE:
CAUTION:
3. Remove:

dust seal 
1

oil seal clip 2
(with a flat-head screwdriver)
Do not scratch the inner tube.
4. Remove:

damper rod assembly bolt
While holding the damper rod assembly with the
damper rod holder 
1 and T-handle 2, loosen
the damper rod assembly bolt.
Damper rod holder
90890-01294
T-handle
90890-01326
5. Remove:

inner tube
a. Hold the front fork leg horizontally.
b. Securely clamp the brake caliper bracket in a
vise with soft jaws.
c. Separate the inner tube from the outer tube
by pulling the inner tube forcefully but care-
fully.

Excessive force will damage the oil seal
and bushing. A damaged oil seal or bush-
ing must be replaced.

Avoid bottoming the inner tube into the
outer tube during the above procedure, as
the oil flow stopper will be damaged. 
						

							4-50
FRONT FORKCHAS
WARNING
CAUTION:
EAS00657
CHECKING THE FRONT FORK LEGS
The following procedure applies to both of the
front fork legs.
1. Check:

inner tube 
1

outer tube 2
Bends / damage / scratches 
 Replace.
Do not attempt to straighten a bent inner
tube as this may dangerously weaken it.
2. Measure:

spring free length 
a
Out of specification 
 Replace.
Spring free length
354 mm (13.94 in)
 : 347 mm (13.66 in)
3. Check:

damper rod 
1
Damage / wear 
 Replace.
Obstruction 
 Blow out all of the oil pas-
sages with compressed air.

oil flow stopper 
2
Damage 
 Replace.

The front fork leg has a built-in damper ad-
justing rod and a very sophisticated inter-
nal construction, which are particularly
sensitive to foreign material.

When disassembling and assembling the
front fork leg, do not allow any foreign ma-
terial to enter the front fork.
4. Check:

cap bolt O-ring
Damage / wear 
 Replace. 
						

							4-51
FRONT FORKCHAS
WARNING
NOTE:
WARNING
CAUTION:
23 Nm (2.3 m
kg, 17 ft
lb)
NOTE:
EAS00659
ASSEMBLING THE FRONT FORK LEGS
The following procedure applies to both of the
front fork legs.

Make sure the oil levels in both front fork
legs are equal.

Uneven oil levels can result in poor han-
dling and a loss of stability.

When assembling the front fork leg, be sure to
replace the following parts:
– inner tube bushing
– outer tube bushing
– oil seal
– dust seal
– before assembling the front fork leg, make
sure all of the components are clean.
1. Install:

inner tube busing

outer tube busing

oil flow stopper

damper rod assembly 
1

copper washer New
Always use new copper washer.
Allow the damper rod assembly to slide
slowly down the inner tube until it protrudes
from the bottom of the inner tube. Be careful
not to damage the inner tube.
2. Lubricate:

inner tube’s outer surface
Recommended lubricant
Suspension oil “01” or
equivalent
3. Tighten:

damper rod assembly bolt 
1
LOCTITE
While holding the damper rod assembly with the
damper rod holder 
2 and T-handle 3, tighten
the damper rod assembly bolt. 
						

							4-52
FRONT FORKCHAS
CAUTION:
NOTE:
NOTE:Damper rod holder
90890-01294
T-handle
90890-01326
4. Install:

outer tube bushing 
1
(with the fork seal driver weight 2 and fork
seal driver attachment 
3)
Fork seal driver weight
90890-01367
Fork seal driver attachment
90890-01374
5. Install:

washer

oil seal 
1
(with the fork seal driver weight and fork seal
driver attachment)
Make sure the numbered side of the oil seal
faces up.

Before installing the oil seal, lubricate its lips
with lithium-soap-based grease.

Lubricate the outer surface of the inner tube
with fork oil.

Before installing the oil seal, cover the top of
the front fork leg with a plastic bag 
2 to protect
the oil seal during installation.
6. Install:

oil seal clip 
1
Adjust the oil seal clip so that it fits into the outer
tube’s groove. 
						

							4-53
FRONT FORKCHAS
CAUTION:
NOTE: 7. Install:

dust seal 
1
(with the fork seal driver weight)
Fork seal driver weight
90890-01367
8. Fill:

front fork leg
(with the specified amount of the recom-
mended fork oil)
Quantity (each front fork leg)
0.467 L (0.41 Imp qt, 0.49 US qt)
Recommended oil
Suspension oil “01” or
equivalent

Be sure to use the recommended fork oil.
Other oils may have an adverse effect on
front fork performance.

When disassembling and assembling the
front fork leg, do not allow any foreign ma-
terial to enter the front fork.
9. Measure:

front fork leg oil level 
a
Out of specification 
 Correct.
Front fork leg oil level (from the 
top of the inner tube, with the
inner tube fully compressed and
without the fork spring)
134 mm (5.28 in)

While filling the front fork leg, keep it upright.

After filling, slowly pump the front fork leg up
and down to distribute the fork oil. 
						

							4-54
FRONT FORKCHAS
NOTE:
NOTE:
30 Nm (3.0 m
kg, 22 ft
lb)
24 Nm (2.4 m
kg, 17 ft
lb)
30 Nm (3.0 m
kg, 22 ft
lb)
WARNING
10. Install:

spring 
1

spring seat 2

spacer 3

cap bolt

Install the spring with the smaller pitch 
a fac-
ing up.

Before installing the cap bolt, lubricate its O-
ring with grease.
bLarger pitch
EAS00662
INSTALLING THE FRONT FORK LEGS
The following procedure applies to both of the
front fork legs.
1. Install:

front fork leg
Temporarily tighten the upper and under
bracket pinch bolts.
Make sure the inner fork tube is flush with the
top of the upper bracket.
2. Tighten:

under bracket pinch bolt 
1

cap bolt 2

upper bracket pinch bolt 3
Make sure the brake hoses are routed prop-
erly.