2005–2006 Honda CRF450R Service Manual (OEM)

• Honda factory service manual for the 2005–2006 CRF450R, presented in a 355-page PDF.
• Covers the complete 449.4 cc, 12.0:1 engine, constant-mesh 5-speed transmission, chassis, suspension, hydraulic brakes, carburetion, cooling, and ICM ignition systems.
• Includes exploded component views, torque tables, service limits, maintenance schedules, and a dedicated Wiring Diagram. Named reference views and charts include Cable & Harness Routing, the Lubrication System Diagram, Tuning Information Chart, and Coolant Gravity Chart.
• Separates important '05 and After '05 (2006) changes instead of treating both years as identical, including carburetor calibration, engine-mount torque values, cable/harness routing, front-fork oil and damping settings, and rear-shock setup data. No VIN/serial-number coverage range is stated; model-year differences are identified by those year labels.

Workshop Reference Overview

This Honda service manual goes well beyond routine maintenance. Engine sections cover compression testing, valve-clearance and decompressor adjustment, camshaft and cam-chain service, valve-guide replacement and valve-seat refacing, cylinder/piston inspection, clutch repair, kickstarter and gearshift-linkage repair, crankcase separation, transmission inspection and assembly, crankshaft measurement, balancer timing, and oil-pump service. Honda also makes the service boundary clear: the cylinder head, piston, clutch, carburetor, flywheel, water pump, and balancer can be serviced with the engine in the frame, while crankcase, crankshaft, transmission, and oil-pump work require engine removal.

The fuel-system section covers the FCR carburetor through removal, disassembly, assembly, float-level measurement, accelerator-pump inspection, pilot-screw setup, throttle-position-sensor replacement, and temperature/altitude jetting charts. The model-year split is specific: the carburetor identification changes from FCR00D ('05) to FCR00E (After '05), with NGGQ versus NCYQ jet needles and pilot-screw initial openings of 1-7/8 versus 1-1/2 turns out. The factory float level is 8.0 mm and idle speed is 1,700 ± 100 rpm.

Chassis repair depth is equally detailed. The fork section covers removal, disassembly, seal and bushing service, damper bleeding/refilling, oil quantity, and installation checks. Rear-suspension coverage includes shock bladder and damper service, valve-stack handling, linkage and swingarm bearing replacement, shock-oil filling, and nitrogen charging. Hydraulic-brake procedures include fluid replacement and air bleeding plus master-cylinder and caliper overhaul. Electrical diagnosis is not limited to a wiring schematic: it includes ICM troubleshooting, ignition-coil testing, exciter-coil and ignition-pulse-generator peak-voltage checks, ignition-timing inspection, engine-stop-button testing, and TPS inspection.

Special-tool references are built into the repair procedures. Examples include clutch center holder 07724-0050002, valve spring compressor 07757-0010000, water-seal driver 07945-KA30000, fork-seal driver 07VMD-KZ30100, and peak-voltage adaptor 07HGJ-0020100; the U.S.-only IgnitionMate tester is identified as MTP07-0286.

Specification Highlights

The manual provides the measurements needed to judge parts before reassembly. Cooling-system capacity is 1.11 liters at coolant change and 1.20 liters at disassembly, with radiator-cap relief pressure of 108–137 kPa (16–20 psi). Cylinder compression is 539 kPa (78 psi) at 600 rpm. Valve clearance is 0.16 ± 0.03 mm intake and 0.28 ± 0.03 mm exhaust. Engine-oil capacity is 0.66 liter at draining, 0.69 liter with filter change, and 0.85 liter at disassembly; transmission oil is 0.59 liter at draining and 0.67 liter at disassembly. TPS resistance is 4–6 kΩ at 20°C (68°F).

For suspension setup, the '05 fork uses 382 cm³ per fork tube and 195 cm³ in the fork damper, versus 375 cm³ and 190 cm³ After '05. Standard compression damping changes from 11 to 8 clicks out, while rebound changes from 7 to 9 clicks out. The rear shock is charged with nitrogen at 980 kPa (142 psi); oil capacity changes from 385 cm³ to 395 cm³, and standard spring installed length from 256.3 mm to 256.7 mm. These are meaningful 2005/2006 differences when rebuilding or returning suspension to factory baseline.

Several manual-specific repair cautions are worth knowing before opening the engine. Installing the oil filter backward can cause severe engine damage. The titanium intake valves must not be lapped because lapping damages their thin oxide coating. Honda also specifies new piston-pin clips during reassembly; reusing old clips can lead to serious engine damage.

Honda states that this repair information is intended for qualified professional technicians, and some procedures require dedicated equipment. The rear shock is a high-pressure nitrogen unit, the cooling system is pressurized, and hydraulic-brake work uses DOT 4 fluid. The manual supplies factory service procedures and baseline settings, while referring the reader to the Owner's Manual for pre-ride inspection and detailed rider-specific suspension setup.