Yamaha EK40G, Service Manual

Page: 22 / 200

Electrical
Item Unit
Model
EK40GMH EK40JMH EK40JW
Ignition and ignition control
system
Ignition timing (full retard) Degree BTDC 9 at engine idle speed
Ignition timing (full advanced) Degree BTDC 23
Ignition spark gap mm (in) 0.6–0.7 (0.024–0.028)
Ignition coil resistance
Primary coil (O–B)
Ω
0.26–0.35
at 20°C (68°F)
SPEC
2-5 6H95G11
Specifications
Item Unit
Model
EK40GMH EK40JMH EK40JW
Carburetor
ID mark 6F542 6H903
Kerosene Gasoline Kerosene Gasoline
Main jet (M.J.) # 145 – 140 –
Main air jet (M.A.J.) ø1.70 – ø1.70 –
Main nozzle (M.N.) mm (in) 3.2 (0.13) – 3.2 (0.13) –
Pilot jet (P.J.) # 90 60 90 60
Pilot air jet (P.A.J.) ø1.00 ø1.20 ø1.00 ø1.20
Pilot screw (P.S.) turns out 3/4 – 1 1/4 3/4 – 1 1/4
Valve seat size mm (in) 2.0 (0.08) 1.2 (0.05) 2.0 (0.08) 1.2 (0.05)
Float height mm (in) 12.0–13.0 4.0–5.0 12.0–13.0 4.0–5.0
(0.47–0.51) (0.16–0.20) (0.47–0.51) (0.16–0.20)
Lower unit
Item Unit
Model
EK40GMH EK40JMH EK40JW
Gear backlash
Pinion-to-forward mm (in)
Pinion-to-reverse mm (in)
Pinion gear shims mm
Forward gear shims mm
Reverse gear shims mm
0.05–0.24
(0.0020-0.0094)
0.40–0.59
(0.0157–0.0232)
0.70, 0.75,
0.80, 0.85
0.70, 0.80,
0.90,
1.00, 1.10, 1.20
1.80, 1.90, 2.00,
2.10, 2.20, 2.30,
2.40, 2.50
0.19–0.47
(0.0075-0.0185)
0.76–1.04
(0.0299–0.0409)
0.05, 0.08, 0.12, 0.30, 0.50
0.05, 0.08, 0.12, 0.30, 0.50
0.05, 0.08, 0.12, 0.30, 0.50
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