Yamaha YFM90RA manual 30

ENGINE SPECIFICATIONS

SPEC

Item

Standard

Limit

Piston rings

Top ring

Type

B

Barrel

----

T

Dimensions (B ⋅ T)

1.0 × 2.1 mm

----

(0.0394 × 0.0827 in)

End gap (installed)

0.10 ~ 0.25 mm

0.45 mm

(0.0039~0.0098in)

(0.0177in)

Side clearance (installed)

0.015 ~0.055 mm

0.09 mm

2nd ring

(0.0006~0.0022in)

(0.0035in)

B

Type

T

Taper

----

Dimensions (B ⋅ T)

1.0 × 2.0 mm

----

0.0394 × 0.0787 in)

End gap (installed)

0.25 ~ 0.40 mm

0.55mm

(0.0098~0.0157in)

(0.0217in)

Side clearance

0.015 ~ 0.055 mm

0.09mm

Oil ring

(0.0006~0.0022in)

(0.0035in)

B

Dimensions (B ⋅ T)

T

2.0 × 1.9 mm

----

(0.0787 × 0.0748 in)

End gap (installed)

0.20 ~ 0.70 mm

----

(0.0079~0.0276in)

Crankshaft

F

C2

C1

E

D

A

Crankwidth “A”

44.10~44.15mm

----

(1.7362~1.7382in)

Runout limit C1

----

0.04 mm

(0.0016in)

C2

----

0.04 mm

(0.0016in)

Big end side clearance “D”

0.10~0.30mm

0.50 mm

(0.0039~0.0118in)

(0.0197in)

Big end radial clearance “E”

0.007~0.015mm

----

(0.0003~0.0006in)

Small end free play “F”

0.80~1.00mm

1.50mm

(0.0315~0.0394in)

(0.0591in)

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