Yamaha F4B Service Manual

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Power unit technical data
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(*1) The figures are for reference only.
Power unit technical data
Power unit
(*1) Measuring conditions: Ambient temperature 20 °C (68 °F), wide open throttle, with spark plug
removed from cylinder.
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. The figures are for reference only.
Manual starter
(*1) The figures are for reference only.
Carburetor
Float height (*1) mm (in)
10.0 (0.4)
Valve seat size mm (in)
0.8 (0.03)
Main jet (MJ) # 60
# 70 # 75
Main nozzle mm (in) 1.6 (0.06)
2.0 (0.08) 2.4 (0.09)
Pilot jet (PJ) # 35
#42
Pilot air jet (PAJ) # 105
# 110
Adjustable pilot screw (PS) turns out 1 3/8 ± 3/4
2 1/8 ± 3/4 2 1/4 ± 3/4
Fuel pump
Holding pressure
Inlet positive pressure
kPa (kgf/
cm
2
, psi)
50.0 (0.50, 7.3)
Outlet positive pressure
kPa (kgf/
cm
2
, psi)
50.0 (0.50, 7.3)
Item Unit
Model
F4BMH F5AMH F6CMH
Cylinder
Minimum compression pres-
sure (*1)
kPa (kgf/
cm
2
, psi)
700.0 (7.00, 101.5)
Thermostat
Valve opening temperature °C (°F) 58–62 (136–144)
Fully open temperature °C (°F) 70 (158)
Fully open stroke mm (in) 3.0 (0.12)
Item Unit
Model
F4BMH F5AMH F6CMH
Starter rope
Length (*1) mm (in) 1800.0 (70.9)
Extended length mm (in) 1430.0–1570.0 (56.3–61.8)
Item Unit
Model
F4BMH F5AMH F6CMH
Electrical technical data / Fuel system technical data / Power unit technical data

Yamaha F4B Specifications

General

Brand	Yamaha
Model	F4B
Category	Outboard Motor
Language	English