2006–2012 Honda TRX680FA & TRX680FGA Rincon Service Manual (OEM)

• Covers 2006–2012 Honda TRX680FA and TRX680FGA FourTrax Rincon models. The manual separates many specifications and circuits into '06/'07 and After '07 data, with GPS-model and regional U.S., Australia, and Canada callouts where applicable.
• 596-page Honda Service Manual PDF covering scheduled maintenance, factory specifications, diagnostics, engine and chassis repair, and model-year-specific wiring diagrams.
• Covers the longitudinal OHV PGM-FI engine and Rincon drivetrain: torque converter, three hydraulically operated shift clutches, 3-speed automatic/ESP operation, D-N-R sub-transmission, and selectable 2WD/4WD.

Contents and Factory Data

The manual starts with vehicle identification data, including VIN and engine serial number locations plus the throttle-body identification number. It also makes the early/late production split visible instead of treating all years as mechanically identical. The throttle body changes from GQ67A on '06/'07 models to GQ60A after '07; fuel-tank capacity changes from 17.0 liters to 16.3 liters, and selected torque specifications, harness routing, brake fittings, differential hardware, and wiring diagrams are likewise separated by model year.

Engine coverage is built around the longitudinal single-cylinder OHV engine with a 102 x 82.6 mm bore and stroke, 9.2:1 compression ratio, forced-pressure dry-sump lubrication, liquid cooling, and a 40 mm PGM-FI throttle bore. Repair sections go well beyond tune-up work: cylinder head, valves, valve guides and seats, camshaft and followers, cylinder and piston, crankcase, crankshaft and balancer, alternator/starter clutch, recoil starter, sub-transmission, and engine removal/installation are covered with inspection limits, torque values, lubrication points, and required service tools.

Chassis and final-drive coverage includes front and rear suspension, steering shaft and tie-rods, wheel hubs and knuckles, hydraulic brakes, front drive shafts and differential, rear drive shafts, universal joint, and rear final-drive assembly. Frame/body-panel chapters cover service access through the seat, tank covers, fenders, carriers, guards, and meter cover, along with exhaust pipe and muffler removal/installation. Electrical chapters cover the battery/charging system, ignition, electric starter, lights, meters, switches, rear vehicle-speed sensor, and GPS receiver on GPS-equipped models.

Servicing this ATV requires proper mechanical knowledge. Follow the manual's safety precautions, support the vehicle securely before chassis work, relieve fuel pressure before opening the PGM-FI supply side, and use the specified tools and torque values.

Diagnostics, Testing, and Repair Procedures

The PGM-FI section provides symptom troubleshooting, connector locations, a DTC index, circuit-level DTC diagnosis, MIL readout, HDS Pocket Tester use, freeze/current data, fuel-pressure and pump-flow testing, injector and sensor checks, PCM inspection, IACV service, and TP-sensor reset coverage. The PCM also controls the automatic transmission and selectable 4WD system, so the drivetrain chapter adds its own DTC troubleshooting, gear-position and drive-mode switch testing, shift-solenoid checks, valve-body service, and hydraulic pressure testing.

Factory procedures cover work that owners commonly send to a shop: engine removal and installation, valve-guide replacement and valve-seat refacing, crankcase separation, crankshaft/balancer and bearing service, torque-converter removal and inspection, shift-clutch/mainshaft repair, front differential and rear final-drive overhaul, ring-and-pinion backlash/contact-pattern inspection, brake-fluid replacement and bleeding, master-cylinder/caliper repair, cooling-system pressure testing, and water-pump service.

Special-tool references are specific enough for workshop planning. Examples include oil-pressure gauge set 07406-0020005, SCS connector 070PZ-ZY30100, fuel-pressure gauge 07406-0040004, differential inspection tool 07KMK-HC50101/07KMK-HC5010A, and torque-converter puller 07933-HA80000/07933-HB3000A. Named technical graphics include the Lubrication System Diagram, PGM-FI System Diagram, Cooling System Flow Pattern, Shift Clutch Hydraulic Circuit and Operation, Drivetrain System Diagram, and separate full wiring diagrams for '06/'07 and After '07 TRX680FA/FGA models. The wiring sheets identify PCM/ECM/TCM connections, relays, fuses, switches, sensors, solenoids, wire colors, GPS circuitry, and Australia-specific horn wiring.

The manual also flags repair mistakes that can damage components. The throttle body is factory preset; disturbing the white-painted fasteners can cause throttle-body malfunction. During engine removal, the shift-valve-body solenoids must not be used as handholds or struck because shock can damage them. Rear final-drive service also accounts for the extra leverage of the lock-nut wrench so the lock nut is not overtightened by confusing actual torque with the torque-wrench reading.

Quick Reference Specifications

• Engine displacement: 674.9 cc
• Engine oil capacity: 2.7 L after draining; 2.9 L with filter change; 4.1 L after disassembly
• Radiator/engine coolant capacity: 2.0 L; reserve tank: 0.46 L; radiator-cap relief pressure: 108–137 kPa (16–20 psi)
• Idle speed: 1,400 ± 50 rpm
• Fuel pressure: 336–350 kPa (48.8–50.8 psi); fuel-pump flow: 150 cm³ minimum in 10 seconds
• Valve clearance, cold: IN 0.15 mm / EX 0.33 mm
• A/T line and 1st/2nd/3rd shift-clutch oil pressure: 785 kPa (114 psi) at 5,000 rpm, 80°C/176°F
• Front differential gear backlash: 0.05–0.25 mm; service limit 0.4 mm