Ignition System - Honda 1998 VT750C Service Manual

17. IGNITION SYSTEM
SYSTEM DIAGRAM
SERVICE INFORMATiON
TROUBLESHOOTING
IGNITION SYSTEM INSPECTION
SERVICE INFORMATION
17-0
17-1
17-3
17-4
IGNITION CONTROL MODULE (lCM) 17-7
IGNITION COIL 17-7
IGNITION TIMING 17-8
GENERAL
mI!IIIIL- _
If the engine must be running to do some work, make sure the area is well-ventilated. Never run the engine in an enclosed
area. The exhaust contains poisonous carbon monoxide gas that may cause loss
of
the consciousness and may lead to
death. Run the engine in an open area or with an exhaust evacuation system in an enclosed area.
CAUTION:
Some electrical components may be damaged if terminals or connectors are connected or disconnected while the ignition
switch is ON and a current is present.
• When checking the ignition system, always follow the steps in the troubleshooti ng (page 17-3).
• Ignition timing cannot be adjusted since the Ignition Control Module (ICM) is non-adjustable. If ignition timing is incorrect,
check the system components and replace any faulty parts.
• The ICM may be damaged if dropped. Also, if the connector is disconnected when current is flowing, the resulting
excessive voltage may damage the unit. Always turn off the ignition switch before servicing.
• A faulty ignition system is often related to poorly connected or corroded connectors. 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 plugs.
• Use spark plugs of the correct heat range. Using a spark plug of an incorrect heat range can damage the engine.
• For neutral switch and side stand switch inspection and removal/installation see section 19.
• For engine stop switch and ignition switch inspection and removal/installation see section 13, 19.
SPECIFICATIONS
ITEM
SPECIFICATIONS
Spark plug NGK DENSO
Standard
DPR8EA 9
X24EPR-U9
For cold climate (below 5°C/4" F)
DPR7EA 9
X22EPR-U9
For extended high speed riding
DPR9EA 9
X27EPR-U9
Spark plug gap
0.80 - 0.90 mm (0.031 - 0.035 in)
Ignition coil primary peak voltage 100 V minimum
Ignition pulse generator peak voltage 0.7 V minimum
Ignition timing "F" mark 8° BTDC at 1,000 rpm
Advance
Start
3,000
±
200 rpm
Stop
5,500
±
200 rpm
Full advance 24.5° BTDC at 5,500 rpm
17-1