Yamaha F50 Service Manual

62Y3A116-32
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Shimming
NOTE:
Shimming is not required when assembling
the original lower case and inner parts.
Shimming is required when assembling the
original inner parts and a new lower case.
Shimming is required when replacing the
inner parts.
Selecting the pinion shims
1. Calculate the specified value (M0) as
shown in the examples below.
NOTE:
“P” is the deviation of the lower case dimen-
sion from standard. The “P” mark a
 is
stamped on the trim tab mounting surface of
the lower...

LOWRLower unit
6-3362Y3A11
5. Measure the clearance (M) between the
shim selecting tool and the pinion as
shown.
NOTE:
Measure the pinion at three points to find the
clearance average.
6. Select the pinion shims (T3).
NOTE:
The sum of T3 and M should not be more
than M0.
Selecting the forward gear shims
1. Calculate the specified value (M0) as
shown in the examples below.
NOTE:
“F” is the deviation of the lower case dimen-
sion from standard. The “F” mark a
 is
stamped on the trim tab mounting surface...

62Y3A116-34
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2. Install the taper roller bearing 1
 to the
shim selecting tools.
NOTE:
Tighten the nut four turns after it contacts the
spring.
3. Measure the clearance (M) between the
gauge pin and press plate.
4. Select the forward gear shims (T1).
NOTE:
The sum of T1 and M should not be more
than M0.
Selecting the reverse gear shims
1. Measure the backlash to find the neces-
sary shim thickness (T2). Add or remove
shims if out of specification. For measur-
ing procedures, see...

LOWRLower unit
6-3562Y3A11
Shimming (F50A) (for worldwide)6 

62Y3A116-36
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Shimming
NOTE:
Shimming is not required when assembling
the original lower case and inner parts.
Shimming is required when assembling the
original inner parts and a new lower case.
Shimming is required when replacing the
inner parts.
Selecting the pinion shims
1. Install the drive shaft and drive shaft
bearing 1
 to the shimming tools.
NOTE:
Select the shim thickness (T3) by using the
specified measurement(s) and the calcula-
tion formula.
Install the shimming tool to...

LOWRLower unit
6-3762Y3A11
Example:
If “M” is “11.70 mm” and “P” is “+5”, then
T3 = 11.70 – 11.30 – (+5)/100 mm
= 0.40 – 0.05 mm = 0.35 mm
If “M” is “11.70 mm” and “P” is “–5”, then
T3 = 11.70 – 11.30 – (–5)/100 mm
= 0.40 + 0.05 mm = 0.45 mm
5. Select the pinion shim(s) (T3) as follows.
Example:
If “T3” is “0.44 mm”, then the pinion shim is
0.45 mm.
If “T3” is “0.39 mm”, then the pinion shim is
0.40 mm.
Selecting the forward gear shims
1. Turn the taper roller bearing outer race
1
 two or three times to...

62Y3A116-38
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Example:
If “M” is “22.45 mm” and “F” is “+5”, then
T1 = 22.75 + (+5)/100 – 22.45mm
= 0.30 + 0.05 mm = 0.35 mm
If “M” is “22.45 mm” and “F” is “–5”, then
T1 = 22.75 + (–5)/100 – 22.45mm
= 0.30 – 0.05 mm = 0.25 mm
3. Select the forward gear shim(s) (T1) as
follows.
Example:
If “T1” is “0.45 mm”, then forward gear shim
is 0.42 mm.
If “T1” is “0.50 mm”, then forward gear shim
is 0.48 mm.
Selecting the reverse gear shims
1. Measure the backlash to find the shim
thickness (T2)....

LOWRLower unit
6-3962Y3A11
Backlash (F50/F50A)6
Measuring the forward and reverse 
gear backlash
1. Remove the water pump assembly.
2. Set the gearshift to the neutral position.
ÈFor USA and Canada
ÉFor worldwide
3. Install the special service tool so that it
pushes against the propeller shaft.
ÈFor USA and Canada
ÉFor worldwide
NOTE:
Tighten the universal puller or center bolt
while turning the drive shaft until the drive
shaft can no longer be turned.
4. Install the backlash indicator onto the
drive...

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5. Slowly turn the drive shaft clockwise and
counterclockwise and measure the back-
lash when the drive shaft stops in each
direction.
6. Add or remove shims if out of specifica-
tion.
M: Measurement
7. Remove the special service tools from
the propeller shaft.
8. Apply a load to the reverse gear by
installing the propeller 0
 without the
spacer A
, the washer B
 backwards,
then the washer C
 as shown.
NOTE:
Tighten the propeller nut D
 while turning the
drive shaft until...

LOWRLower unit
6-4162Y3A11
Lower unit (T50/FT50B, FT50C)6