Service Information; Ignition Timing - Honda VT750C2 Shadow Spirit Service Manual

IGNI1"ION SYSTEM
SERVICE INFORMATION
GENERAL
NOTICE
• The ICM may be damaged if dropped. Also, if the connector is disconnected when current is flowing, the excessive volt­
age may damage the ICM. Always turn the ignition switch to OFF before servicing. .
• Use spark plugs with the correct heat range. Using spark plugs with an incorrect heat range can damage the engine.
• Some electrical components may be damaged if terminals or connectors are connected or disconnected while the igni ­
tion switch is turned to ON and current is present.
• When servicing the ignition system, always follow the steps in the troubleshooting table on page 19-4.
• The transistorized ignition system uses an electrically controlled ignition timing system. No adjustments can be made
to the ignition timing.
• The ICM varies ignition timing according to the engine speed. The TP sensor signals the ICM to compensate the ignition
timing according to the throttle opening.
• 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 plugs.
• For spark plug inspection (page 4-9).
• Refer to the following components informations:
- Ignition switch (page 21-16)
- Engine stop switch (page 21-17)
- Neutral switch (page 21-19)
- Sidestand switch (page 21-20)
- Diode (page 20-16)
SPECIFICATIONS
ITEM SPECIFICATIONS
Spark plug I Standard
I For extended high speed riding
Spark plug gap
Ignition coil primary peak voltage
DPR6EA-9 (NGK), X20EPR-U9 (DENSO)
DPR7EA-9 (NGK), X22EPR-U9 (DENSO)
0.8 - 0.9 mm (0.03 - 0.04 in)
100 V minimum
Ignition pulse generator peak voltage 0.7 V minimum
Ignition timing ("F"mark) 13° BTDC at idle
TP sensor I Resistance
(20°C/68°F)
I Input voltage
4-6 kn
5V
TORQUE VALUES
Alternator cover socket bolt 10 N'm (1.0 kgf·m, 7 Ibf·ft)
Timing hole cap 10 N'm (1.0 kgf'm, 7 Ibf·ft) Apply grease to the threads
TOOLS
Peak voltage adaptor IgnitionMate peak voltage tester
07HGJ-0020100 (not available in
MTP07-0~86(U.S.A.
only)
U.S.A.)
with commercially available digital
multimeter (impedance 10 MWDCV
minimum) or peak voltage tester
(U.S.A. only)