Model Nickname:
Sportrax 400EX
Vehicle Type:
All-Terrain Vehicle (ATV)
Model Code Variants:
TRX400EX
Production Years Covered:
1999, 2000, 2001, 2002, 2003, 2004
Target Audience:
Honda TRX400EX Sportrax owners, DIY mechanics, repair shops
Dealer Equivalent:
Same type of service manual used by local dealers
Value Proposition:
Saves money on repair and maintenance costs, empowers owners with knowledge
Convenience:
Instant download, printable pages for workshop use, no shipping delays
Customer Satisfaction:
Guaranteed
Engine:
Complete tear down and rebuild, cylinder head, valve, cylinder, piston, lubrication system, fuel system, alternator, starter clutch, crankcase, transmission, crankshaft
Chassis:
Frame, body panels, exhaust system, front wheel, suspension, steering, rear wheel, suspension, swingarm
Brakes:
Hydraulic disc brake system, front and rear brake components, bleeding procedures
Electrical:
Battery, charging system, ignition system, electric starter, lights, switches, wiring diagram
Fuel System Details:
Carburetor (carboretor/carburettor) tuning, jetting (slow jet, main jet, pilot jet), mixture screw adjustment, fuel pump (if applicable, though this model is carbureted), fuel tank, fuel lines
Maintenance:
Scheduled maintenance, fluid changes (coolant, oil), filter replacements, general upkeep
Repair:
Complete rebuild procedures for engine, transmission, suspension, brakes, and electrical components
Troubleshooting:
Diagnostic procedures for common and uncommon issues, 'no spark' diagnosis, performance problems, error code explanations (if applicable to electronic components)
Installation Removal:
Engine removal/installation, component installation and removal procedures for all major systems
Scope Of Repair:
Covers everything from basic maintenance to complete overhaul and restoration
Detail Level:
Highly detailed, FSM preview with pictures, part diagrams, torque specs
Engine Type:
4-stroke, SOHC, longitudinally-mounted single-cylinder
Bore X Stroke:
85.0 mm x 70.0 mm
Horsepower Approximate:
Approx. 28-32 HP (at flywheel, varies by year/tune)
Torque Approximate:
Approx. 25-28 lb-ft (at flywheel, varies by year/tune)
Carburetor Type:
Keihin 34mm flat-slide carburetor
Fuel Capacity:
2.4 US gal (9.1 L), including 0.5 US gal (1.9 L) reserve
Oil Type:
API SG or higher, SAE 10W-40 recommended (specific viscosity based on ambient temperature)
Oil Capacity:
Approx. 1.9 L (2.0 US qt) for oil change, 2.1 L (2.2 US qt) after filter replacement, 2.5 L (2.6 US qt) after engine disassembly
Ignition Type:
CDI (Capacitor Discharge Ignition)
Cooling Method:
Liquid-cooled
Coolant Type:
Honda HP Coolant or equivalent (50/50 mix of ethylene glycol and deionized water)
Transmission Type:
5-speed manual with reverse
Clutch Type:
Wet, multi-plate
Gearshift Linkage:
Standard foot-operated gearshift linkage
Drive Train:
O-ring-sealed chain drive
Transmission Oil Type:
Honda Manual Transmission Fluid (MTF) or equivalent API GL-3/GL-4 gear oil
Transmission Oil Capacity:
Approx. 0.75 L (0.79 US qt)
Dry Weight:
Approx. 341.7 lbs (155 kg)
Curb Weight:
Approx. 363.8 lbs (165 kg)
Length:
Approx. 72.0 in (1830 mm)
Width:
Approx. 45.1 in (1145 mm)
Height:
Approx. 43.2 in (1098 mm)
Wheelbase:
Approx. 49.6 in (1260 mm)
Ground Clearance:
Approx. 4.0 in (102 mm)
Front Tire Size:
AT22 x 7-10
Rear Tire Size:
AT20 x 10-9
Front Wheel Type:
Aluminum alloy
Rear Wheel Type:
Aluminum alloy
Front Suspension Type:
Independent, double wishbone with adjustable spring preload shocks
Rear Suspension Type:
Swingarm with adjustable spring preload shock absorber
Engine Oil Change Interval:
Every 600 miles (1000 km) or 6 months (refer to manual for specific conditions).
Air Filter Cleaning:
Every 200 miles (300 km) or more frequently in dusty conditions.
Spark Plug Inspection:
Every 600 miles (1000 km).
Valve Clearance Check:
Every 600 miles (1000 km) or annually.
Brake Fluid Type:
DOT 3 or DOT 4 Honda Brake Fluid
Coolant Capacity:
Approx. 1.7 L (1.8 US qt)
Common Wear Items:
Brake pads, chain and sprockets, wheel bearings, carburetor jets, swingarm bushings.
Performance Tuning Tips:
Manual covers carburetor tuning (jetting, mixture), which is crucial for optimal performance with aftermarket exhaust or air filter modifications.
