Troubleshooting of electrical (Suzuki Boulevard M109R, 2006-2025) [Information for owner: Troubleshooting]

Complaint	Symptom and possible causes	Remedy
No sparking or poor sparking	1. Defective ignition coils	Replace.
	2. Defective ignition coil/plug caps	Replace.
	3. Defective spark plugs	Replace.
	4. Defective CKP sensor	Replace.
	5. Defective ECM	Replace.
	6. Defective TO sensor	Replace.
	7. Open-circuited wiring connections	Check and repair.
Spark plug soon become fouled with carbon.	1. Mixture too rich	Inspect FI system.
	2. Idling speed set too high	Adjust throttle valve synchronization and idling speed.
	3. Incorrect gasoline	Change.
	4. Dirty air cleaner element	Replace.
	5. Too cold spark plugs	Replace with hot type plug.
Spark plug become fouled too soon.	1. Worn piston rings	Replace.
	2. Worn piston or cylinders	Replace.
	3. Excessive clearance of valve stems in valve guides	Replace.
	4. Worn stem oil seal	Replace.
Spark plug electrodes overheat or burn	1. Too hot spark plugs	Replace with cold type plugs.
	2. Overheated the engine	Tune up.
	3. Loose spark plugs	Retighten.
	4. Too lean mixture	Inspect FI system.
Generator does not charge.	1. Open- or short-circuited lead wires, or loose lead connections	Repair or replace or retighten.
	2. Short-circuited, grounded or open generator coil	Replace.
	3. Short-circuited or punctured regulator/rectifier	Replace.
Generator does charge, but charging rate is below the terminals.	1. Lead wires tend to get shorted or open-circuited or loosely connected at	Repair or retighten.
	2. Grounded or open-circuited generator coil specification.	Replace.
	3. Defective regulator/rectifier	Replace.
	4. Defective cell plates in the battery	Replace the battery.
Generator overcharges	1. Internal short-circuit in the battery	Replace the battery.
	2. Damaged or defective regulator/rectifier	Replace.
	3. Poorly grounded regulator/rectifier	Clean and tighten ground connection.
Unstable charging	1. Lead wire insulation frayed due to vibration, resulting in intermittent short-circuiting.	Repair or replace.
	2. Internally shorted generator	Replace.
	3. Defective regulator/rectifier	Replace.
Starter button is not effective.	1. Run down battery	Repair or replace.
	2. Defective switch contacts	Replace.
	3. Brushes not seating properly on starter motor commutator	Repair or replace.
	4. Defective starter relay/starter interlock switch	Replace.
	5. Defective main fuse	Replace.

Troubleshooting of electrical (Suzuki Boulevard M109R)