CYLINDER AND PISTON

ENG

Cylinder bore “C”

95.00 ~ 95.01 mm

(3.7402 ~ 3.7406 in)

 

 

 

Taper limit “T”

0.05 mm (0.002 in)

 

 

Out of round “R”

0.05 mm (0.002 in)

 

 

“C” = Maximum D

 

“T” = (Maximum D1 or D2)

– (Maximum D5 or D6)

“R” = (Maximum D1, D3 or D5)

(Minimum D2, D4 or D6)

If out of specification, replace the cylinder, and replace the piston and piston rings as set.

2nd step:

Measure the piston skirt diameter “P” with

a micrometer.

a8 mm (0.315 in) from the piston bottom edge

Piston size “P”

Standard

94.945 ~ 94.960 mm

(3.738 ~ 3.739 in)

 

If out of specification, replace the piston and piston rings as a set.

3rd step:

Calculate the piston-to-cylinder clearance with following formula:

Piston-to-cylinder clearance = Cylinder bore “C” – Piston skirt diameter “P”

Piston-to-cylinder clearance: 0.040 ~ 0.065 mm

(0.0016 ~ 0.0026 in) <Limit>: 0.1 mm (0.004 in)

If out of specification, replace the cylinder, and replace the piston and piston rings as set.

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Image 167
Yamaha WR45OFR Cylinder bore C 95.00 ~ 95.01 mm 7402 ~ 3.7406, 05 mm 0.002, 2nd step, Piston size P Standard, 738 ~ 3.739