Honda TRX400 FA FGA 2004-2007 Fourtrax Rancher Service Manual

Honda's own factory specifications confirm the core engine spec across this range: a 397cc air-cooled OHV dry-sump longitudinally mounted single-cylinder four-stroke, delivering power through Honda's Hondamatic fully automatic transmission — a genuine automatic drivetrain, distinct from the electric-shift ESP systems used on other Honda models of the era. The TRX400FA runs the standard configuration, while the TRX400FGA adds Honda's factory GPScape navigation system, sharing an otherwise identical mechanical foundation.

A long-term owner's own real-world testing on the Honda ATV Forum offers genuinely useful field data for this platform: on a 264-mile, three-day trip carrying 80 lbs of gear and a 220-lb rider across terrain ranging from 6,000 to 10,000 feet above sea level, the 400FA AT returned roughly 70 miles per tank before switching to reserve — leading that owner to recommend planning fuel stops every 50 miles or carrying extra fuel on extended backcountry trips. The same owner found genuinely strong performance climbing steep grades, reaching 54 mph "with still throttle to go," though noting that speed felt like plenty for a working utility ATV rather than something to push further.

Standard equipment across both variants includes selectable 4WD with the same fundamental driving mechanism architecture Honda applied across its Rancher and Foreman lines during this era, a full suspension system at front and rear, and Honda's dry-sump lubrication delivering genuinely reliable oil circulation for sustained off-road use. The factory service manual for this generation runs through comprehensive coverage: general information and technical features, frame and body panel service, engine lubrication and fuel systems, complete engine teardown from cylinder head and camshaft through cylinder and piston work, the centrifugal clutch, alternator and starter clutch, sub-transmission and gearshift linkage, crankshaft and automatic transmission service, front and rear suspension and steering, the brake system, front and rear driving mechanisms, battery and charging, ignition, electric starter, and a dedicated Selectable 4WD System and Hondamatic transmission section — genuinely essential given how much additional mechanical complexity the automatic Hondamatic drivetrain adds over a simpler manual-shift ATV. The Honda ATV Forum discussion notes candidly that "all models of ATV's have issues — none are perfect," specifically flagging the Hondamatic transmission as one of the areas most worth watching and understanding on this 2004-2007 generation.

This factory service manual covers the procedures, torque specs, and diagrams needed to keep a 2004-2007 TRX400FA/FGA FourTrax Rancher AT running the way it was built to.