1999-2002 Honda TRX400EX Specs

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Manufacturer: Honda

Year: 1999, 2000, 2001, 2002

Model: TRX400EX

Model Code: HN1

Frame Starting Number 1999: 478TE230*XA000001

Frame Starting Number 2000: 478TE230*Y4000001

Engine Starting Number 1999: TE23E-8000001

Engine Starting Number 1999: TE23E-8000001


Length: 72.2in (1835mm)

Width: 45.3in (1150mm)

Height: 43.7in (1110mm)

Seat Height: 31.9in (810mm)

Wheelbase: 48.4in (1230mm)

Ground Clearance: 4.3in (110mm)

Footpeg Height: 13.9in (353mm)

Dry Weight: 375lbs (170kg)

Curb Weight: 392lbs (178kg)

Weight Capacity: 243lbs (110kg)

Caster Angle: 6.5in

Camber Angle: -0.8in

Trail: 1.1in (28mm)

Tie-rod distance between ball joints: 14.57in (370.2mm)

Toe: Toe-in 0.1-1.3in (2-32mm)

Fuel Tank Capacity: 2.6 US Gal (10 Liters, 2.2 Imp Gal)

Fuel Tank Reserve: 0.42 US Gal (1.6 Liters, 0.35 Imp Gal).

Drive Chain Slack: 1 1/4 - 1 5/8in (30-40mm)

Tire & Rim

Tire Type: Tubeless

Front Tire Size: 22x7x10

Rear Tire Size: 20x10x9

Tire Pressure: 4psi (27 kPa, 0.275 kgf/cm2)

Front Rim Size: 10in

Rear Rim Size: 9in

Front Tire Model: Ohtsu M/R 101

Rear Tire Model: Ohtsu M/R 501


Engine Type: Single Cylinder 4 Stroke

Fuel Type: Regular Gasoline

Displacement: 397cc (24.2ci)

Bore x Stroke: 85 x 70mm (3.35 x 2.76in)

Compression Ratio: 9.1:1

Cylinder Compression: 100-128psi (686-883 kPa, 7-9 kgf/cm2)

Engine Dry Weight: 91lbs (41.5kg)

Valve Train: SOHC with Rocker Arms

Starting System: Electric Start

Lubrication System: Forced Pressure (Dry Sump)

Oil Pump Type: Trochoid

Cooling System: Air Cooled

Engine Oil Capacity (Total): 2.3 US qt (2.2 Liters, 1.9 Imp qt)

Engine Oil Capacity (Change): 1.95 US qt (1.8 Liters, 1.6 Imp qt)

Engine Oil Capacity (Change + Filter): 1.95 US qt (1.85 Liters, 1.63 Imp qt)

Engine Oil Type: 10W40 or 20W50 SF or SG classification


Clutch System: Multiplate, wet

Clutch Operation: Cable

Transmission type: Constant mesh, 5 speed

Primary Reduction: 2.826 (23/65)

Final Reduction: 2.533 (15/38)

Gear Ratio 1st: 2.916 (12/35)

Gear Ratio 2nd: 1.937 (16/31)

Gear Ratio 3rd: 1.473 (19/28)

Gear Ratio 4th: 1.181 (22/26)

Gear Ratio 5th: 1.000 (26/26)

Gearshift Pattern: 1 - N - 2 - 3 - 4 - 5

Gearshift Operation: Left Foot


Carburetor: Keihin

Carburetor Type: Piston Valve

Throttle Bore: 38mm (1.5in)

ID Mark: QB10A

Main Jet: #148

Jet Needle Clip Position: 3rd groove from top

Pilot/Slow Jet: #38

Pilot Screw: 2 1/4 Turns Out

Fuel Level: 0.73in (18.5mm)

Engine Idle: 1400rpm

Air Filter: Oiled Urethane Foam


Ignition System: ICM (Capacitive Discharge Ignition)

Spark Plug (standard): NGK DPR8Z, Denso X24GPR-U

Spark Plug (extended high speed riding): NGK DPR9Z, Denso X27GPR-U

Spark Plug Gap: 0.024-0.028in (0.6-0.7mm)

Pulse Generator/Pickup Coil Voltage: 0.7v minimum

Exciter Coil Peak Voltage: 100v minimum

Ignition Timing: 8 Degrees BTDC

Ignition Timing Advancement Type: Electrical


Generator System: Flywheel Magneto

Battery: 12v 8Ah

Voltage: 12v

Wattage: 147w @ 5000rpm

Charging System: Single Phase AC Alternator

Regulator/Rectifier: Single Phase Full Wave Rectification

Charging Coil Resistance: 0.1-1.0 ohms


Brake Fluid: DOT 4

Front Brake Operation: Right Hand

Rear Brake Operation: Right Foot

Front Brake Type: Hydraulic Disc x2

Rear Brake Type: Hydraulic Disc


Front Suspension: Double wishbone

Front Wheel Travel: 8.2in (209mm)

Rear Suspension: Swingarm

Rear Wheel Travel: 9.1in (230mm)