Honda CR500R 1985–1991 Service & Repair Manual (P/N 61KA509)

Honda factory shop manual for the 1985–1991 CR500R, P/N 61KA509, covering maintenance, diagnosis, and engine and chassis repair.

Chapter Bookmarks and PDF Text Search

Search, navigation, and wiring detail: PDF text search is not available. Embedded bookmarks cover the chapters and wiring diagrams. Small wire-color labels on the later wiring diagram are best read enlarged.

One printable, English-language, 259-page PDF, including the cover and contents page.

Engine Teardown, PJ Carburetor Tuning, and Chassis Service

This selection of covered work is not a full contents list. Other topics include the competition maintenance schedule, lubrication points, cable and harness routing, and the optional-parts list.

• Engine and drivetrain repair: Engine removal and installation, top-end service, clutch and gearshift work, kickstarter repair, crankcase separation, transmission service, and crankshaft inspection.

• Fuel system and race setup: PJ carburetor repair, starting/idle, slow, and main-circuit theory, altitude and temperature correction, optional jetting parts, float setting, and reed-valve inspection.

• Cooling system: Radiator-cap pressure testing, cooling-system leak checks, radiator removal and installation, and water-pump bearing, oil-seal, and water-seal replacement.

• Front chassis: Front-wheel service, fork disassembly and reassembly, bushing and seal replacement, damping-component inspection, and steering-stem bearing service.

• Rear suspension: Rear-wheel service, swingarm and linkage inspection, shock reservoir and bladder service, damper overhaul, oil filling, air bleeding, and nitrogen charging.

• Brake repair: Rear drum and hydraulic disc brake service, pad and disc inspection, brake-fluid replacement, air bleeding, and master-cylinder and caliper repair.

• Ignition and fault finding: Alternator, pulse-generator, ignition-coil, timing, and engine-stop-switch tests, CDI diagnosis, year-specific wiring diagrams, and symptom-based troubleshooting charts.

Its repair depth and special-tool requirements make it suited to experienced owners and technicians equipped for precision inspection, engine teardown, hydraulic-brake service, and suspension work.

Top-End and Crankcase Repair

Top-end service can be performed with the engine in the frame; crankshaft and transmission work requires engine removal and crankcase separation. Exploded crankcase and transmission views accompany runout checks, gear and bearing measurements, inspection limits, and component-specific torque tables.

Transmission data distinguishes the post-1987 changes, while later engine procedures include callouts marked “After '88.” Matching these distinctions before selecting parts or inspection limits helps avoid applying an earlier assembly’s specifications to a later one.

Crankshaft inspection includes connecting-rod play checks, with out-of-limit assemblies specified for replacement. Top-end cautions explain how rotating the cylinder during assembly can snag and break the piston rings.

PJ Carburetor Identification and Tuning

Carburetor identification changes from PJ21A (1985) and PJ24A (1986) to PJ27A (1987), PJ27B (1988), and PJ27C (after 1988). Separate jet, needle, clip-position, and air-screw data support the different configurations.

Circuit schematics explain which metering system controls each throttle range. An air-density correction graph and Jet Needle/Air Screw Chart support adjustments for altitude and temperature, with additional guidance for specific track conditions.

Step-by-step procedures cover throttle-valve, float, float-valve, and jet service. The jet block is not intended to be removed from the carburetor body. Fuel-tank service and air cleaner case removal are also covered.

Cooling-System Diagnosis and Water-Pump Repair

The cooling chapter connects radiator-cap and system pressure tests with leak diagnosis. Water-pump procedures extend to shaft inspection, bearing replacement, and water-seal replacement, including the inspection-hole check for coolant leakage.

Fork, Shock, and Brake Differences

Front-fork instructions distinguish the 1985, 1986–1988, and after-1988 arrangements, with corresponding component views and assembly procedures. Steering-stem service includes bearing and race replacement.

The 1985–1986 shock uses a separate reservoir connected by a hose; later versions integrate the reservoir with the damper. Shock component views support rod-guide, seal, piston, and valve service.

Setup limit: Standard spring assembly settings are included, but detailed adjustment of spring preload for rider weight and damping for riding conditions is referred to the separate Owner’s Manual.

Brake coverage separates the 1985–1986 rear drum from the hydraulic rear disc used after 1986. Master-cylinder and caliper layouts accompany bore, piston, seal, and disc inspections.

Ignition Diagnosis and Workshop Tools

The wiring diagrams distinguish 1985, 1986, and after-1986 systems. CDI diagnosis uses elimination of other ignition faults before unit replacement, supported by resistance tests and timing checks.

Troubleshooting charts address hard starting, power loss, overheating, clutch drag or slip, low- and high-speed running faults, and poor handling.

General service rules and Honda tool references accompany the procedures. Examples include crankcase puller 07937-4300000, water-seal driver 07945-KA30000, 1985–1988 fork-seal tools 07947-KA40200 and 07947-KA50100, and steering-stem socket 07916-KA50100.

Honda specifies the installation direction of rear-linkage and shock mounting bolts and warns that ordinary replacement bolts lack the required strength.

Fuel-system work, hydraulic-brake service, and gas-charged shock disassembly carry specific hazards. Follow the manual’s ventilation, brake-dust, pressure-release, and nitrogen-only precautions, and support the motorcycle securely before chassis repair.

Preview: Transmission Oil Quantities and Piston Clearances

The lubrication specifications distinguish transmission oil quantity by service condition: 650 cc at an oil change and 700 cc after disassembly. A temperature-based viscosity chart accompanies the oil recommendations.

For cylinder-to-piston clearance, the standard range is 0.050–0.085 mm for 1985–1986 and 0.070–0.105 mm after 1986. These are standard clearances rather than wear limits; the top-end inspection tables list the corresponding service limits separately.