Owner's Manual DF250AP, DF300AP Troubleshooting

• THIS ENGINE IS CERTIFIED TO OPERATE ON UNLEADED GASOLINE OF 89 OCTANE ((R+M)/2 METHOD) OR GREATER.
• EXHAUST EMISSION CONTROL SYSTEM: ECM, MFI, HO2S

This troubleshooting guide is provided to help you find the cause of common complaints.

Failure to troubleshoot a problem correctly can damage your outboard motor. Improper repairs or adjustments may damage the outboard motor instead or fixing it. Such damage may not be covered under warranty.
If you are not sure about the proper action to correct a problem, consult your Suzuki marine dealer.

Starter motor will not operate:

• Emergency stop switch lock plate is not in position.
• Starter relay fuse is blown out.
• Sub battery cable fuse is blown out.
• Control handle is not in NEUTRAL.
• Battery terminal connection is corroded or lost.
• Battery power is lost.
• Starter motor is failed.
• Main switch or start & stop switch is failed.
• Electric wiring connection is loose.

Engine will not start (hard to start):

• Fuel tank is empty.
• Fuel is deteriorated.
• Engine starting procedure is not correct.
• Fuel tank air vent is not opened.
• Fuel hose is not properly connected to engine.
• Fuel hose is kinked or pinched.
• Fuel filter is clogged.
• Fuel pump is failed.
• Fuel tank filter is clogged.
• Spark plug is fouled.
• Ignition system is fouled.
• Electric wiring connection is loose.

Engine idles unstably or stalls:

• Spark plug is fouled.
• Fuel hose is kinked or pinched.
• Fuel hose is not properly connected to engine.
• Fuel is deteriorated.
• Fuel filter is clogged.
• Fuel pump is failed.
• Ignition system is fouled.
• Incorrect engine oil is used.
• Thermostat is failed.
• Electric wiring connection is loose.

Caution system is activated (Caution buzzer sounds. Caution LEDs light.):

• Cooling water passage is clogged.
• Thermostat is failed.
• Water pump is failed.
• Oil change reminder system is activated.
• Engine oil level is low or oil has deteriorated.
• Engine oil filter is clogged.
• Oil pump is failed.
• Propeller is damaged.
• Battery power is lost.
• Engine control sensor is failed.
• Electric wiring connection is loose.

Shift operation will not be activated:

• Electronic shift control system is failed.

Propeller is not rotated:

• Propeller bush is worn or damaged.
• Drive shaft is damaged.
• Propeller shaft is damaged.

Engine speed will not increase:

• Propeller is damaged.
• Propeller is not clean.
• Propeller is not properly selected.
• Outboard motor is not correctly installed.
• Trim angle is not properly adjusted.
• Spark plug is fouled or incorrectly selected.
• Fuel hose is kinked or pinched.
• Fuel filter is clogged.
• Fuel is deteriorated.
• Fuel pump is failed.
• Ignition system is failed.
• Electronic throttle system is failed.
• Heavy cargo is on the boat.
• Water has entered into the boat.
• Bottom of boat is not clean or damaged.

Engine vibrates excessively:

• Propeller is damaged.
• Engine mounting bolts or clamp screws are loose.

The Keyless Start System does not turn ON even when the main switch is operated. The error sound (five short buzzer
beeps) is NOT heard: (If equipped with Keyless Start System)

• Emergency stop switch lock plate is not in position.
• The main switch has been operated continuously while the communication with the keyfob is disabled.
• Battery terminal connection is corroded or lost.
• Battery power is lost.
• Keyless control unit failure.
• Electric wiring connection is loose.
• Main panel failure.

The Keyless Start System does not turn ON even when the main switch is operated. The error sound (five short buzzer
beeps) IS heard: (If equipped with Keyless Start System)

• Key-fob is outside the operating range.
• Key-fob battery is dead.
• Key-fob is in OFF mode.
• The key-fob is not authenticated.
• Communication failure due to strong radio wave or noise.
• Electric wiring connection failure between the keyless control unit and outboard motor.
• Authentication error between the keyless control unit and outboard motor.
• Abnormality exists in the electronic control system of the engine.

The Keyless Start System does not turn OFF even when the main switch is operated:

• Electric wiring connection is loose.
• Main panel failure.

1. If equipped with Keyless Start System:

Turn the Keyless Start System OFF.

If not equipped with Keyless Start System:

Turn the main switch to the “off” position.

2. Remove the motor cover.

3. Remove the fuse box cover and pull off the fuse.

Use the fuse puller at the back of fuse box cover, when the fuse is pulled off and installed.

4. Remove the sub battery cable fuse.

5. Inspect the fuse and replace with new fuse if needed.

If a fuse is blown, try to determine the root cause and correct it.
If the cause is not corrected, the fuse may be blown again.

If you replace a blown fuse with a fuse having a different amperage rating or with a substitute such as aluminum foil or a wire, extensive electrical system damage and a fire may result.
Always replace a blown fuse with a fuse of the same type and rating.

If a new fuse blows in a short time after installation, you may have a major electrical system problem.
Consult your SUZUKI marine dealer.

(1) Ignition coil/Injector/Engine control module/
High pressure fuel pump fuse: 30 A
(2) Starter motor relay fuse: 30 A
(3) Throttle valve fuse: 15 A
(4) Shift actuator fuse: 15 A
(5) PTT switch fuse: 10 A
(6) Low pressure fuel pump fuse: 15 A
(a) Main fuse: 60 A
(b) Isolator select fuse: 40 A
(c) Spare fuse: 60 A
(d) Spare fuse: 30 A
(e) Spare fuse: 15 A
(f) Sub battery cable fuse: 30 A

Power rated in accordance with NMMA procedure.