Honda Metropolitan CHF50 Service Manual page 265

IGNITION SYSTEM
SERVICE INFORMATION
GENERAL
• 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 sequence on page 16-4.
• The ignition timing cannot be adjusted since the Engine Control Module (ECM) is factory preset.
• The ECM may be damaged if dropped. Also, if the connector is disconnected when current is following, the excessive
voltage may damage the ECM. Always turn the ignition switch to "OFF" before servicing.
• A faulty ignition system is often related to poor connected or corroded connectors. Check those connections before pro-
ceeding.
• Although the engine control unit is controlling ignition timing according to engine speed fundamentally, ignition timing
is assisted also with the signal from the throttle position sensor and ECT sensor.
• Use a spark plug of the correct heat range. Using a spark plug with an incorrect heat range can damage the engine.
• For ignition switch and ECT sensor inspection, refer to page 18-16.
• For ignition pulse generator (alternator stator) removal/installation, refer to page 11 -4.
SPECIFICATION
ITEM
Spark plug Standard
For cold climate (below 5 °C/41 °F)
For extended high speed riding
Spark plug gap
Ignition coil peak voltage
Ignition pulse generator peak voltage
Ignition timing ("F" mark)
Throttle position sensor Resistance (20 °C/68 °F)
Input voltage
SPECIFICATIONS
CR8EH-9 (NGK), U24FER9 (DENSO)
CR7EH-9 (NGK), U22FER9 (DENSO)
CR9EH-9 (NGK), U27FER9 (DENSO)
0.80 - 0.90 mm (0.031 - 0.035 in)
80 V minimum
0.7 V minimum
10°BTDC at 2,000 rpm
4-6kft
4.7 - 5.3 V
TOOLS
Peak voltage adaptor
07HGJ-0020100
with commercially available digital
multimeter (impedance 10 Mfi/DCV
minimum)
IgnitionMate peak voltage tester
(U.S.A. only)
16-3