Yamaha F50 Service Manual

62Y3A116-22
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No. Part name Q’ty RemarksTightening torques
Stage N·mkgf·mft·lb
1 Shift rod assembly 1
2 Drive shaft 1
3 Oil seal 1
Not reusable
4 Oil seal housing 1
5 O-ring 1
Not reusable
6 Circlip 1
7 Shift rod 1
8 O-ring 1
Not reusable
9 Taper roller bearing 1Not reusable
10 Bearing outer race 1Not reusable
11 Pinion shim—As required
12 Sleeve 1
13 Oil seal housing assembly 1
14 Washer 1
15 Oil seal housing 1
16 O-ring 1
Not reusable
17 Oil seal 2Not reusable
18 Seal 1
19 Plate 1
20...

LOWRLower unit
6-2362Y3A11
Removing the drive shaft
1. Remove the drive shaft assembly and
pinion, and then pull out the forward
gear.
ÈFor USA and Canada
ÉFor worldwide
Disassembling the drive shaft 
assembly
1. Install the pinion nut 1
, tighten it finger
tight, and then remove the drive shaft
bearing 2
 using a press.
ÈFor USA and Canada
ÉFor worldwide
CAUTION:
•Do not press the drive shaft threads 
a
directly.
•Do not reuse the bearing, always
replace it with a new one.
Disassembling the forward...

62Y3A116-24
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Disassembling the lower case
1. Remove the taper roller bearing outer
race and shim(s).
ÈFor USA and Canada
ÉFor worldwide
NOTE:
Install the claw as shown.
2. Remove the drive shaft bearing outer
race, shim(s), and drive shaft sleeve.
ÈFor USA and Canada
ÉFor worldwide
NOTE:
Install the claw as shown.
3. Remove the needle bearing.
4. Remove the shift rod assembly and shift
cam. Slide hammer and adapters 1
: YB-06096 
Bearing outer race puller 2
: 90890-06523
Outer race...

LOWRLower unit
6-2562Y3A11
Checking the pinion and forward 
gear
1. Check the teeth of the pinion, and the
teeth and dogs of the forward gear for
cracks or wear. Replace the pinion or
gear if necessary.
Checking the bearings
1. Check the bearings for pitting or rum-
bling. Replace if necessary.
Checking the drive shaft
1. Check the drive shaft for bends or wear.
Replace if necessary.
Checking the shift rod and shift cam
1. Check the shift rod and shift cam for
cracks or wear. Replace if necessary....

62Y3A116-26
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2. Install the needle bearing into the lower
case to the specified depth.
ÈFor USA and Canada
ÉFor worldwide
NOTE:
Install the needle bearing with the manufac-
ture identification mark b
 facing upward.
When using the driver rod, do not strike the
special tool in a manner that will force the
stopper c
 out of place.
3. Install the sleeve, original shim(s), and
bearing outer race.
CAUTION:
Add or remove shims, if necessary, when
replacing the pinion or lower case.
NOTE:...

LOWRLower unit
6-2762Y3A11
4. Install the forward gear original shim(s)
and taper roller bearing outer race.
CAUTION:
Add or remove shims, if necessary, when
replacing the forward gear or lower case.
Assembling the forward gear
1. Install the new taper roller bearing into
the forward gear using a press.
ÈFor USA and Canada
ÉFor worldwide
Assembling the drive shaft
1. Install the new drive shaft bearing into
the drive shaft using a press.
ÈFor USA and Canada
ÉFor worldwide
NOTE:
Use a special service tool...

62Y3A116-28
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2. Install the new oil seals to the oil seal
housing as shown.
ÈFor USA and Canada
ÉFor worldwide
Installing the drive shaft
1. Install the forward gear, then the drive
shaft assembly, pinion, and pinion nut,
and then tighten the nut to the specified
torque.
ÈFor USA and Canada
ÉFor worldwide
Installing the lower unit
1. Set the gearshift to the neutral position at
power unit and lower unit.
Oil seal installer 3
: YB-06168
Driver handle 4
: YB-06071
Needle bearing attachment...

LOWRLower unit
6-2962Y3A11
2. Install the two dowel pins 1
 to the lower
unit.
3. Install the lower unit to the upper case,
and then tighten the bolts to the specified
torque.
4. Install the trim tab 2
 to its original posi-
tion, and then connect the speedometer
hose 3
.5. Install the propeller and propeller nut,
tighten the nut finger tight. Place a block
of wood between the anti-cavitation plate
and propeller to keep the propeller from
turning, and then tighten the nut to the
specified torque....

62Y3A116-30
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 WARNING
Do not hold the propeller with your hands
when loosening or tightening it. Be sure
to remove the battery leads from the bat-
teries and the engine shut-off switch. Put
a block of wood between the cavitation
plate and propeller to keep the propeller
from turning.
NOTE:
If the grooves in the propeller nut 4
 do not
align with the cotter pin hole, tighten the nut
until they are aligned.
Propeller nut 4
:
35 N·m (3.5 kgf·m, 25 ft·lb)
Drive shaft and lower case (F50/F50A) 

LOWRLower unit
6-3162Y3A11
Shimming (F50) (for USA and Canada)6