Yamaha BEARTRACKER YFM250XC, Service Manual

Page: 198 / 398

6 - 12
DRIV
In the example above, the calculated shim
thickness is 0.57 mm. The chart instructs
you, however, to round off the 7 to 5, then
shim thickness is 0.55 mm.
Shim selection
ı
● When the crankcase and/or the driven pin-
ion gear are replaced, be sure to adjust
the driven pinion gear shim
ı
.
● To find driven pinion gear shim thickness
“B” use following formula:
c
= The stamped number on the crankcase
is added to from “110”.
d
= The stamped number on the crankcase
is substracted from “59”.
e
= Bearing (driven pinion gear) thickness
(considered constant) “13.00 mm”.
f
= The stamped number on the driven
pinion gear is added to or substracted
from “37.5”.
Example:
1)
If the drive pinion gear is stamped “45”
.....
c
= 110 + 0.45 = 110.45
2) If the crank case is stamped “–02”
.....
d
= 59 - 0.02 = 58.98
3) If the driven pinion gear is stamped
“+02”
.....
f
= 37.5 + 0.02 = 37.52
4) Therefore, shim thickness
ı
is,
ı
= 110.45 – 58.98 – 13.00 – 37.52 =
0.95 mm
5) Shim sizes are supplied in following
thickness:
Because shims can only be selected in 0.05
mm increments, round off hundredths digit
and select appropriate shim(s).
Driven pinion gear shim thickness:
ı
=
c
–
d
–
e
–
f
Drive pinion gear
shim
Thickness (mm)
0.15 0.40
0.20 0.50
0.30
MIDDLE GEAR SERVICE
6