Yamaha 250GETO Service Manual page 197

3. Calculate the propeller shaft shim thick-
ness (T4) as shown in the examples
below.
a b
NOTE:
"A" and "B" are the deviations of the propeller
shaft housing dimensions from standard. The
"A" mark a and "B" mark b are stamped on
the propeller shaft housing in 0.01 mm units.
If the "A" mark or "B" mark is unreadable,
assume that "A" and "B" are zero and check
the free play when the unit is assembled.
Calculation formula 1:
Propeller shaft shim thickness (T4) =
28.00 – A/100 – B/100 – M6 – M7
Example:
If "M6" is 14.75 mm and "M7" is 12.50 mm
and "A" is (– 3) and "B" is (– 5), then
T4 = 28.00 + (–3)/100 – (– 5)/100 –
14.75 – 12.50 mm
= 28.00 + 0.03 + 0.05 – 14.75 – 12.50 mm
= 0.83 mm
If "M6" is 14.75 mm and "M7" is 12.50 mm
and "A" is (+ 7) and "B" is (– 6), then
T4 = 28.00 + (+ 7)/100 – (– 6)/100 –
14.75 – 12.50 mm
= 28.00 + 0.03 + 0.06 – 14.75 – 12.50 mm
= 0.88 mm
6S35H11
4. Round the numerals for the propeller
shaft shim(s) (T4) as follows.
Calculated numeral
at 1/100th place
Example:
If "T4" is 0.83 mm, then the propeller shaft
shim is 0.82 mm.
S69J6626
If "T4" is 0.88 mm, then the propeller shaft
shim is 0.85 mm.
5. Calculate and select the propeller shaft
shim thickness (T'4) as shown in the
examples below.
Calculation formula 2:
Propeller shaft shim thickness (T'4) =
T4 – 0.30
Example:
If "T4" is 0.82 mm, then
T'4 = 0.82 – 0.30 mm
= 0.52 mm
If "T4" is 0.85 mm, then
T'4 = 0.85 – 0.30 mm
= 0.55 mm
Available shim thicknesses:
0.10, 0.12, 0.15, 0.18, 0.30, 0.40 and
0.50 mm
6. If the "A" mark or "B" mark is unreadable,
measure the propeller shaft free play as
shown.
Shimming (counter rotation model)
Rounded numeral
1, 2
3, 4, 5
6, 7, 8
9, 10
1
0
2
5
8
2
3
4
5
6
7
8
9
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