Manual Starter; Cylinder Head Assembly - Yamaha F25 Service Manual

Item
Engine oil
Oil pressure (*2)
at 60 °C (140 °F) with SL
10W-30 engine oil and at
950 r/min
Thermostat
Valve opening temperature
Fully open temperature
Fully open stroke
(*1) Measuring conditions: Ambient temperature 20 °C (68 °F), wide open throttle, with spark plugs
removed from all cylinders.
When pulling the starter handle to crank the engine, the compression pressure may vary depending on
the speed at which the starter handle is pulled. (Manual starter model) The figures are for reference
only.
(*2) For details of the checking method, see "Checking the oil pressure" (7-1). The figures are for reference
only.

Manual starter

Item
Starter rope length
Starter rope extended length

Cylinder head assembly

Item
Cylinder head
Warpage limit
Valve stem
Diameter
Intake
Exhaust
Runout
Intake and exhaust
Valve guide
Inside diameter
Intake and exhaust
Stem-to-guide clearance
Intake
Exhaust
Installation position
Valve spring
Free length
Tilt
Fuel system technical data / Power unit technical data
Unit
F25EA
kPa
2
(kgf/cm ,
psi)
°C (°F)
°C (°F)
mm (in)
Unit
F25MHA
mm (in) 2100.0 (82.7)
1700.0–1900.0
mm (in)
(66.9–74.8)
Unit
F25MHA
mm (in)
mm (in) 5.475–5.490 (0.2156–0.2161)
mm (in) 5.460–5.475 (0.2150–0.2156)
mm (in)
mm (in) 5.500–5.512 (0.2165–0.2170)
mm (in) 0.010–0.037 (0.0004–0.0015)
mm (in) 0.025–0.052 (0.0010–0.0020)
mm (in)
mm (in)
mm (in)
Model
F25A
250.0 (2.50, 36.3)
58.0–62.0 (136–144)
70.0 (158)
3.0 (0.12)
Model
F25EHA
—
—
Model
F25EHA
0.10 (0.0039)
0.010 (0.0004)
16.3–16.7 (0.64–0.66)
39.9 (1.57)
1.7 (0.07)
T25A
1
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