Cold And Warm Engine Ignition Timing Control - SELVA MARINE Kingfish 25 Service Manual

Cold and warm engine ignition timing control

The ignition timing is corrected as shown in the following graph according to the engine cooling
water temperature.
Control-starting condition
–20 °C (–4 °F) or more and 10 °C (50 °F) or
less
More than 10 °C (50 °F) and less than 30 °C
(86 °F)
30 °C (86 °F) or more and 70 °C (158 °F) or
less
More than 70 °C (158 °F)
a
6.0
5.0
4.0
3.0
2.0
1.0
0.0
–1.0
–2.0
–3.0
–4.0
–5.0
–6.0
–20
(–4)
a Ignition timing correction (degree)
b Cooling water temperature (°C [°F])
c Basic ignition timing
10 30
(50) (86)
Corrected ignition timing
BTDC 5 degrees
Returns from BTDC 5 degrees to the basic
ignition timing
Basic ignition timing
Corrected from the basic ignition timing to
ATDC 5 degrees
50 60
(122) (140)
Ignition control system
c
b
70 90
(158) (194)
2
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