Yamaha 250GETO, Service Manual

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GEN
INFO
1-23 6S35H11
General information
Ignition control
The micro-computer controls the ignition timing due to the throttle valve angle and engine RPM at
every 0.01 seconds.
When starting the engine, the ignition timing is fixed to BTDC7.
If the engine condition is in an emergency, the ignition is controlled to misfire.
1) Warm-up control
When starting a cold engine, the ignition timing range is controlled by the engine temperature as
below.
2) Over-rev control
This engine has an over-rev limiter.
When the engine speed exceeds 6,100 rpm for example jumping with boat, misfire is immediately
started to prevent the engine from damage because of over-rev.
For detail ignition control, see the table below.
NOTE:
If the wire (Gy) of CDI unit has been cut off, the over-rev limiter is no longer activated.
This is a tuning for competition use.
If the gray wire is cut off, the warranty never covers your outboard motor.
Engine temp. Ignition timing
Above 40
°
C (104
°
F) ATDC4-BTDC20
30-40
°
C (86-104
°
F) BTDC2-BTDC20
Below 30
°
C (86
°
F) BTDC4-BTDC20
Engine RPM Misfiring cylinder
Below 6,099 Non
6,100 - 6,124 One of 6-cylinder
6,125 - 6,149 Two of 6-cylinder
6,150 - 6,174 Three of 6-cylinder
6,175 - 6,199 Four of 6-cylinder
6,200 - 6,224 Five of 6-cylinder
Above 6,225 All (6-cylinder)
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