Honda CB900F Service Manual page 378

17. IGNITION SYSTEM
SYSTEM DIAGRAM
SERVICE INFORMATION
TROUBLESHOOTING
IGNITION SYSTEM INSPECTION
SERVICE INFORMATION
GENERAL
17-0
17-1
17-3
17-4
ICGNITION COIL
IGNITION PULSE GENERATOR
IGNITION TIMING
ECM (ENGINE CONTROL MODULE)
17-7
17 -7
17-10
17 -11
Some electrical components may be damaged if terminals or connectors are connected or disconnected while the igni-
tion switch is ON and current is present.
When servicing the ignition system, always follow the steps in the troubleshooting sequence on page 17-3.
This motorcycle's Ignition Control Module (ICM) is built into the Engine Control Module IECM!.
The ignition timing does not normally need to be adjusted since the ECM is factory preset.
The ECM may be damaged if dropped.
Also if the connector is disconnected when current is
flowing, the excessive volt-
age may damage the module. Always turn off the ignition switch before servicing .
A faulty ignition system is often related to poor connections. Check those connections before proceeding . Make sure the
battery is adequately charged. Using the starter motor with a weak battery results in a slower engine cranking speed as
well as no spark at the spark plug .
Use spark plug of the correct heat range . Using spark plug with an incorrect heat range can damage the engine.
Refer to section 5 for Throttle Position (TP) sensor, cam pulse generator and ECM inspection.
SPECIFICATIONS
ITEM SPECIFICATIONS
Spark plug (Iridium! NGK CR8EH·9IStandard!/ CR9EH·9 (Forextended high speed running!
DENSO
U24fER9IStandard!/ U27FER9 (Forextended high speed running!
Spark plug gap 0.80 - 0.90 mm 10.031 - 0.035 in!
Ignition coil peak voltage 100 V minimum
Ignition pulse generator peak voltage 0.7 V minimum
Ignition timing I"F" mark)
8"
BTDC at idle
17-1