Kawasaki STX-15F service manual Troubleshooting Guide, Engine Doesn’t Start, Starting Difficulty

16-32 APPENDIX

Troubleshooting Guide

NOTE

○This is not an exhaustive list, giving every possible cause for each problem listed. It is meant simply as a rough guide to assist the troubleshooting for some of the more common difficulties.

Engine Doesn’t Start, Starting Difficulty

Starter motor not rotating

Starter motor trouble (brushes worn) Battery voltage low

Starter relay not contacting or operating Start button not contacting

Wiring open or shorted Ignition switch trouble Engine stop switch trouble Fuse blown

Starter motor rotating but engine doesn’t turn over

Reduction gear trouble Vehicle-down sensor (DFI) coming off

Engine won’t turn over

Valve seizure

Valve lifter seizure Cylinder, piston seizure Crankshaft seizure Connecting rod small end seizure Connecting rod big end seizure Camshaft seizure

No fuel flow No fuel in tank

Fuel tank air vent obstructed

Fuel pump screen and/or fuel filter clogged Fuel injector trouble

Fuel line clogged

Engine flooded

Clean spark plug and adjust plug gap Starting technique faulty (When flooded, do

not crank the engine with the throttle fully opened. This promotes engine flood be- cause more fuel is supplied automatically by DFI.)

No spark; spark weak Ignition coil faulty

Vehicle-down sensor (DFI) coming off Vehicle-down sensor trouble

Ignition switch turned OFF and/or lanyard key not pushed under stop button

Battery voltage low

Spark plug dirty, broken, or gap malad- justed

Ignition coil shorted or not in good contact Ignition coil trouble

Spark plug incorrect Spark plug cap trouble

Spark plug cap shorted or not in good con- tact

IC igniter in ECU trouble Camshaft position sensor trouble Crankshaft sensor trouble Wiring shorted or open

Fuse blown

Fuel/air mixture incorrect Air passage clogged Air filter poorly sealed Fuel injector trouble

Water or foreign matter in fuel Throttle sensor trouble

Fuel pressure may be low Fuel pump trouble

Inlet air pressure sensor trouble Inlet air temperature sensor trouble Water temperature sensor trouble Crankshaft sensor trouble

Compression Low

Spark plug loose

Cylinder head not sufficiently tightened down

No valve clearance Cylinder, piston worn

Piston ring bad (worn, weak, broken, or sticking)

Piston ring/groove clearance excessive Cylinder head gasket damaged Cylinder head warped

Valve spring broken or weak

Valve not seating properly (valve bent, worn, or carbon accumulation on the seating surface)

Poor Running at Low Speed

Spark weak Battery voltage low

Spark plug dirty, broken, or maladjusted Ignition coil shorted or not in good contact Ignition coil trouble

Spark plug incorrect Spark plug cap trouble

Spark plug cap shorted or not in good con- tact

IC igniter in ECU trouble Camshaft position sensor trouble Crankshaft sensor trouble

Fuel/air mixture incorrect Air passage clogged Air filter poorly sealed Fuel tank air vent obstructed Fuel pump trouble

Inlet air duct loose

Fuel pump screen and/or fuel filter clogged Throttle body assy loose

Throttle body assy gasket damage