1998-2004 Honda Foreman 450 factory service manual, Page 379Get this manual
IGNITION SYSTEM
TROUBLESHOOTING
Inspect the following before diagnosing the system:Faulty spark plugLoose spark plug cap or spark plug wire connectionWater got into the spark plug cap (leaking the ignition coil secondary voltage) Temporarily exchange the ignition coil with another one and perform the spark testIf there is spark, the original ignition coil is faulty Before starting troubleshooting, disconnect the alternator 5P connector, and check continuity between the Yellow (ICM connector on the wire harness side) and Yellow on the wire harness side of the alternator connectorNo spark at plug Unusual condition Probable cause (Check in numerical order)
Ignition coil primary voltage
Low peak voltage
1The multimeter impedance is too low2Cranking speed is too low3The sampling time of the tester and measured pulse were not synchronized (System is normal if measured voltage is over the standard voltage at least once)4Poor connection or an open circuit in ignition system5Faulty ignition pulse generator (Measure the peak voltage)6Faulty ICM (Ifabove are normal)