Suzuki DF 2.5 Service Manual (English)

Patricia MoyerAug 4, 2025

What to do if my Suzuki DF 2.5 Outboard Motor has no or weak sparks?

J
Jennifer NewtonAug 4, 2025
If your Suzuki Outboard Motor has no or weak sparks, start by checking the spark plug's condition and replace it if necessary. Then, disconnect the emergency/engine stop switch lead wire (Black) and inspect/replace the emergency/engine stop switch. Also, verify the air gap between the igniter unit core and the flywheel, adjusting it if it's out of specification. Check the igniter unit resistance. Inspect the spark plug cap for high-tension leak evidence and replace it if it's not in good condition. Check the spark plug cap resistance. If the issue persists, consider replacing the igniter unit.

Suzuki DF 2.5 Specifications

General

Engine Type	OHV
Fuel System	Carburetor
Starting System	Manual
Engine Mounting	Bushing Type
Gear Ratio	2.15:1
Gear Shift	F-N
Exhaust	Above Prop Exhaust
Maximum Output	1.8 kW (2.5 PS)
Ignition System	CDI
Fuel Tank Capacity	1.0 L
Weight	13.5 kg
Full Throttle Operating Range	5, 250 rpm
Trim Method	Manual
Bore x Stroke	48 x 38 mm (1.9 x 1.5 in.)

Summary

General Information

Warning, Caution, and Note

Emphasizes special information using signal words like WARNING, CAUTION, and NOTE.

General Precautions

Lists important safety and operational procedures for service mechanics.

Identification Number Location

Shows where to find the model, pre-fix, and serial numbers on the motor.

Fuel and Oil Specifications

Details recommended gasoline types and engine oil specifications.

Engine Break-in and Warm-up

Explains critical break-in period and warm-up recommendations for motor durability.

Propellers and Specifications

Details recommended operating range, selection chart, and technical specifications.

Service Data and Torque

Provides key service data, tightening torques for fasteners.

Special Tools and Materials

Illustrates and lists special tools and required materials for servicing.

Periodic Maintenance

Maintenance Schedule and Chart

Lists recommended intervals and tasks for periodic service work.

Maintenance and Tune-up Procedures

Describes servicing procedures for periodic maintenance requirements.

Engine Oil Maintenance

Details checking and changing engine oil, including level checks.

Gear Oil Maintenance

Provides instructions and intervals for changing the gear oil.

Lubrication and Spark Plug

Details lubrication points and spark plug inspection, gap, and replacement.

Valve Clearance and Idle Speed

Explains checking and adjusting valve clearance and engine idle speed.

Carburetor and Ignition Timing

Describes carburetor inspection and checking ignition timing.

Hoses, Filters, Pumps, and Anodes

Covers inspection and replacement of breather hoses, fuel filters, water pumps, and anodes.

Bolts, Nuts, and Cylinder Compression

Specifies checking bolt tightness and measuring cylinder compression.

Ignition and Electrical

Ignition System Overview and Operation

Outlines the transistorized ignition system components and how it functions.

Ignition Troubleshooting

Provides a flowchart for diagnosing ignition system issues.

Ignition Component Inspection

Details inspection procedures for igniter, spark plug cap, and stop switch.

Igniter and Flywheel Magneto Installation

Covers removal and installation of the igniter unit and flywheel magneto.

Fuel System

Fuel System Safety Precautions

Lists critical safety precautions when working on the fuel system.

Fuel Line Handling

Provides guidance on handling fuel lines during removal and installation.

Carburetor Service

Covers carburetor removal, installation, disassembly, cleaning, and reassembly.

Fuel Tank and Fuel Cock Service

Details removal and inspection procedures for the fuel tank and cock.

Recoil Starter

Recoil Starter Service Procedures

Covers removal, disassembly, inspection, reassembly, and installation of the recoil starter.

Power Unit

Power Unit Removal and Installation

Details the steps for removing and installing the power unit.

Cylinder Head Assembly Service

Covers removal, installation, disassembly, and inspection of the cylinder head assembly.

Engine Core Assembly Service

Guides through disassembly and reassembly of cylinder, piston, crankshaft, conrod, and camshaft.

Engine Core Components Inspection

Details inspection of camshaft, rocker arms, cylinder, piston, rings, and crankshaft clearances.

Thermostat Service

Covers thermostat removal, inspection, and installation.

Cooling and Lubrication Systems

Describes the water cooling and engine oil lubrication systems.

Mid Unit

Driveshaft Housing/Swivel Bracket Service

Covers disassembly, inspection, and reassembly of these components.

Tiller Handle Service

Details removal and disassembly/reassembly of the tiller handle.

Lower Unit

Lower Unit Removal and Disassembly

Details the procedure for removing and disassembling the lower unit.

Lower Unit Component Inspection

Covers inspection of propeller, gears, shafts, water pump, and seals.

Lower Unit Reassembly and Installation

Guides through the reassembly and installation of lower unit components.

Gear Adjustment and Backlash

Explains shimming, backlash adjustment, and tooth contact pattern checks for gears.

Propeller Shaft Thrust Play Check

Details how to measure and adjust propeller shaft thrust play.

Suzuki DF 2.5 Service Manual

Table of Contents

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