Yamaha WR250FM service manual Head diameter Face width Seat width Margin thickness

MAINTENANCE SPECIFICATIONS

SPEC

		Item		Standard		Limit
Timing chain:
Timing chain type/No. of links				92RH2010-114M/114		----
Timing chain adjustment method				Automatic		----
Valve, valve seat, valve guide:
Valve clearance (cold)			IN	0.10 ~ 0.15 mm		----
				(0.0039 ~ 0.0059 in)
			EX	0.17 ~ 0.22 mm		----
				(0.0067 ~ 0.0087 in)
Valve dimensions:
			B	C
	A					D
Head diameter			Face width	Seat width	Margin thickness

“A” head diameter	IN
	EX
“B” face width	IN
	EX
“C” seat width	IN
	EX
“D” margin thickness	IN
	EX
Stem outside diameter	IN
	EX
Guide inside diameter	IN
	EX
Stem-to-guide clearance	IN
	EX

22.9~ 23.1 mm (0.9016 ~ 0.9094 in)

24.4~ 24.6 mm (0.9606 ~ 0.9685 in)

2.26mm (0.089 in)

2.26mm (0.089 in)

0.9~ 1.1 mm (0.0354 ~ 0.0433 in)

0.9~ 1.1 mm (0.0354 ~ 0.0433 in)

0.8mm (0.0315 in)

0.7mm (0.0276 in)

3.975 ~ 3.990 mm

(0.1565 ~ 0.1571 in)

4.460 ~ 4.475 mm

(0.1756 ~ 0.1762 in)

4.000 ~ 4.012 mm

(0.1575 ~ 0.1580 in)

4.500 ~ 4.512 mm

(0.1772 ~ 0.1776 in)

0.010 ~ 0.037 mm

(0.0004 ~ 0.0015 in)

0.025 ~ 0.052 mm

(0.0010 ~ 0.0020 in)

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----

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1.6mm (0.0630 in)

1.6mm (0.0630 in)

----

----

3.945 mm

(0.1553 in)

4.430 mm

(0.1744 in)

4.050 mm

(0.1594 in)

4.550 mm

(0.1791 in)

0.08mm (0.003 in)

0.10mm (0.004 in)

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