DFI System Troubleshooting Guide

Symptoms or possible Causes

Actions (chapter)

Starter motor not rotating:

Ignition and engine stop switches not ON

Turn both switches ON.

Starter lockout switch or neutral switch trouble

Inspect (see chapter 16)

Starter motor trouble

Inspect (see chapter 16).

Battery voltage low

Inspect and charge (see chapter 16).

Starter relays not contacting or operating

Inspect the starter relay (see chapter 16).

Starter button not contacting

Inspect and replace (see chapter 16).

Starter system wiring open or shorted

Inspect the wiring (see chapter 16).

Ignition switch trouble

Inspect and replace (see chapter 16).

Engine stop switch trouble

Inspect and repair or replace (see chapter 16).

Main 30 A or ignition fuse blown

Inspect and replace (see chapter 16).

Starter motor rotating but engine doesn’t

turn over :

Starter clutch trouble

Inspect (see chapter 9).

Starter idle gear trouble

Inspect (see chapter 9).

Engine won’t turn over :

Valve seizure

Inspect and replace (see chapter 5).

Cylinder, piston seizure

Inspect and replace (see chapter 5).

Camshaft seizure

Inspect and replace (see chapter 5).

Connecting rod small end seizure

Inspect and replace (see chapter 9).

Connecting rod big end seizure

Inspect and replace (see chapter 9).

Crankshaft seizure

Inspect and replace (see chapter 9).

Transmission gear or bearing seizure

Inspect and replace (see chapter 9).

Balancer bearing seizure

Inspect and replace (see chapter 9).

No fuel flow :

No or little fuel in tank

Supply fuel (see Owner’s Manual).

Fuel pump not rotating

Inspect (see chapter 3).

Fuel injector trouble

Inspect and replace (see chapter 3).

Fuel tank air vent obstructed

Inspect and repair (see chapter 3).

Fuel filter or pump screen clogged

Inspect and replace fuel pump (see chapter 3).

Fuel pressure regulator clogged

Inspect and replace fuel pump (see chapter 3).

Fuel line clogged

Inspect and repair (see chapter 3).

Engine flooded :

Spark plug dirty, broken or gap maladjusted

Clean spark plugs and adjust plug gap (see

chapter 2).

FUEL SYSTEM (DFI) 3-25

DFI System Troubleshooting Guide

Symptoms or possible Causes

Actions (chapter)

Starting technique faulty

When flooded, don’t crank engine with throttle

fully opened.

No spark or spark weak :

Ignition and engine stop switches not ON

Turn both switches ON .

Clutch lever not pulled in and gear not in neutral

Pull the lever in and shift the gear in neutral.

whether sidestand up or not

Though clutch lever pulled in, sidestand up and

Sidestand down and clutch lever pulled in whether

gear not in neutral

gear in neutral or not

Vehicle-down sensor coming off

Reinstall (see chapter 3).

Vehicle-down sensor trouble

Inspect (see chapter 3) .

ECU ground or power supply trouble

Inspect (see chapter 3) .

Battery voltage low

Inspect and charge (see chapter 16).

Spark plug dirty, broken or gap maladjusted

Clean spark plug and adjust plug gap (see chapter

2).

Spark plug cap trouble

Inspect stick coil (see chapter 16).

Spark plug cap shorted or not in good contact

Reinstall or inspect stick coil (see chapter 16).

Spark plug incorrect

Replace it with the correct plug (see chapter 16).

IC igniter in ECU trouble

Inspect (see chapter 16).

Neutral, starter lockout or sidestand switch

Inspect each switch (see chapter 16).

trouble

Crankshaft sensor trouble

Inspect (see chapter 16).

Stick coil trouble

Inspect (see chapter 16).

Ignition switch shorted

Inspect and replace (see chapter 16).

Engine stop switch shorted

Inspect and repair or replace (see chapter 16) .

Starter system wiring shorted or open

Inspect and repair or replace (see chapter 16).

Main 30 A or ignition fuse blown

Inspect and replace (see chapter 16).

Fuel/air mixture incorrect :

Air cleaner clogged, poorly sealed or missing

Clean or reinstall (see chapter 3).

Leak from oil filler cap, crankcase breather hose

Inspect and repair or replace (see chapter 3).

or air cleaner drain hose

Water or foreign matter in fuel

Change fuel. Inspect and clean fuel system (see

chapter 3).

Fuel pressure regulator trouble

Inspect fuel pressure and replace fuel pump (see

chapter 3).

Main throttle sensor trouble

Inspect (see chapter 3).

Fuel pressure may be low

Inspect (see chapter 3).

Fuel pump trouble

Inspect (see chapter 3).

Fuel injector trouble

Inspect (see chapter 3).

Inlet air pressure sensor trouble

Inspect (see chapter 3).

Atmospheric pressure sensor trouble

Inspect (see chapter 3).

Inlet air temperature sensor trouble

Inspect (see chapter 3).

Water temperature sensor trouble

Inspect (see chapter 3).

Crankshaft sensor trouble

Inspect (see chapter 3).

Compression low :

Spark plug loose

Reinstall (see chapter 16).

Cylinder head not sufficiently tightened down

Tighten (see chapter 5).