1991 Kawasaki JET SKI 650SX (JS650-B1) Service Manual Supplement (P/N 99924-1147-51)

The 1991 Kawasaki JET SKI 650SX (JS650-B1) Service Manual Supplement, P/N 99924-1147-51, documents service and repair changes specific to this model. It requires the X-2 base Service Manual, P/N 99924-1069-01, which is not included in this download.

• Fuel system: Carburetor disassembly, cleaning, reassembly, float-arm inspection, high-altitude adjustment, and model-specific fuel-tank, sediment-bowl, throttle-cable, and choke-cable service.

• Engine and exhaust: Engine removal, revised installation notes, magneto flywheel and coupling service, crankcase assembly changes, and exhaust-manifold gasket orientation.

• Cooling and lubrication: Cooling and bilge flushing, oil-tank removal, and routing and lubrication references for hoses, cables, and steering joints.

• Drive shaft and jet pump: Shaft-holder bearing and seal installation, runout inspection, pump removal differences, and steering-nozzle disassembly notes.

• Steering and hull: Steering-cable replacement, handlebar pivot service, handle-pole removal, hull replacement, and rubber-part attachment guidance.

• Electrical system: Starter-relay testing, electric-case service, CDI igniter removal, revised resistance data, and a wiring diagram with wire-color codes.

Written primarily for Jet Ski mechanics in properly equipped shops, the supplement also supports basic owner maintenance and repair when the reader understands mechanics, tool use, and workshop procedures.

Carburetor Service and Oil-Tank Details

Keihin CDK38-32 coverage includes a fuel-system diagram, diaphragm-needle wear illustrations, and a float-arm level drawing. The mixture-screw section distinguishes individual factory settings from baseline settings used when the original adjustment has been lost.

Fuel-pump disassembly notes explain how stuck assemblies can lead to damaged diaphragms and castings during separation. Sediment-bowl service covers drainage, removal, and O-ring inspection.

The lubrication chapter adds oil-tank capacity, mounting, and damper details. Oil-pump bleeding and reed-valve inspection are referenced to the base manual.

Engine Installation and Drive-Shaft Repair

Engine-bottom-end exploded views identify the crankcase, magneto flywheel, and stator. Assembly notes address cylinder locating pins and the crankshaft position ring; full crankcase splitting and internal engine inspection remain in the base manual.

The coupling section identifies flywheel holder 57001-1313 and coupling holder 57001-1230. Torque and locking-agent tables cover cylinder-head nuts, engine-bed mounting bolts, shaft-holder fasteners, and pump components, alongside the general tuning specifications and periodic maintenance chart.

The drive-shaft holder cross-section shows bearing and seal placement, while the runout drawing identifies measurement locations. Installation notes address coupling alignment. Pump removal notes identify the B1's lack of a trim-cable connector; impeller-clearance inspection is referenced to the base manual.

Cooling, Steering, and Hull Work

The cooling/bilge flow illustration distinguishes cooling water, bilge flow, and combined exhaust-water paths. Flushing procedures address salt and sand deposits and suspected bilge blockages.

Cable-routing drawings support steering-cable replacement and handle-pole service. Hull instructions cover pad removal, engine-hood gasket bonding, and damper placement for the fuel tank, engine, and water box muffler. Storage notes address sediment-bowl drainage and flame-arrester access.

Working on marine engines and fuel systems carries inherent risks. Follow the manual's safety precautions and appropriate shop practices.

Starter-Relay and Ignition Checks

The starter-relay section includes return and activated-resistance tests. Charging-coil connection changes, start/stop-switch lead identification, and the CDI internal-resistance matrix supplement the base electrical procedures.

The regulator/rectifier lead changes from white to orange on the JS650-B1, helping match the base manual's test procedure to the correct wiring. Electric-case instructions warn that unsuitable silicone sealant can corrode electrical connectors.

Exploded views show starter-motor components, but complete starter-motor overhaul procedures remain in the base manual.

Examples of Coupling Torques and Inspection Limits

A few values illustrate the supplement's assembly and inspection data. The engine coupling is listed at 98 N-m (72 ft-lb), while the drive-shaft coupling is listed at 39 N-m (29 ft-lb).

Drive-shaft runout has a standard of less than 0.2 mm and a service limit of 0.6 mm. For the carburetor, the float-arm level is 1.0-2.0 mm, measured between the arm's plastic tip and the carburetor case as illustrated.

Printable PDF with Chapter Bookmarks

Navigation, search, and diagram detail: Embedded bookmarks cover the main chapters; the appendix has no bookmark. PDF text search is unavailable. Small wiring-diagram labels are readable when enlarged.

One printable English PDF contains 83 pages: 80 numbered chapter pages plus three introductory quick-reference and foreword pages, all included in the total.