CF MOTO CF125T-19 2003, Руководство по обслуживанию

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16
16-3
16 Ignition system
Troubleshooting
• Engine cannot be started.
Check fuel and air gateways for any faults; If the fuel and air gateways are normal, check the ignition
system.
• Inspect of ignition system for the following items:
1. Spark inspection:
Check in the following steps:
Take off spark plug
Remove spark plug cap
Set high tension flexible cable end to earthing
Check spark arc
It is normal if spark arc is more than 8mm ， while it is weak if it is less than 5 mm 。
If the spark is normal, check the spark plug 。
A faulty spark plug may be caused by the following reasons:
(1) Spark plug is too wet and drowned. This is because the mixture is too thick. Cut the fuel and start
the engine several times..
(2) Carbon deposit on spark plug — Mixture too thick or oil burnt in the combustion chamber. Clean
and burnish the spark plug.
(3) Cracks with spark plug insulator.
(4) Two poles of spark plug have short circuit or it is obstructed between negative pole and thread
or positive pole and input end.
2. Faulty spark includes: no spark and weak spark.
Inspect the following aspects if there is no spark.
(1). Inspect ignition coil in substitution way with multimeter or measurement.
1) Measure primary bobbin resistance, usually it is about 1 Ω .
2) Measure secondary bobbin resistance, usually it is about 4.2K Ω .
3) Measure damp resistance, usually it is about 5K Ω .
(2). Check CDI in the substitution way to check if it is out of service.
(3). Check ignition circuit. Usually the voltage between blue/black wire and earthing wire (green) should
be 12V. If there is no voltage, check from the battery positive terminal to the end of blue/black wire.
(4). Check the cable: check if there are any faults from the input of trigger signal (output of magneto
trigger) to output (CDI terminal) and ignition output wire (black/yellow).
(5). Check stop switch. When switch is at the stop position, black/white wire should be disconnected
with green wire.
In case of weak spark, check the following:
(1). Check CDI in the substitution way.
(2). Check ignition coil and secondary coil whether there is short circuit, or fault with the damp resistance.