JS550 Model Updates
- B on vin denotes following model year (e.g., an 82B would not be yellow) (possible theory)
- 1982 JS550 – First Year, Model Introduced
- Machine Specs:
- Engine:
- Color: Black
- Style: Piston Port, 2 stroke
- Displacement: 530cc
- Cylinders: Dual Cylinder
- Compression Ratio: ??????????????????
- Piston Rings: 1 Thick Ring
- Crankshaft: T-bone style
- Spark Plug: B8ES
- Carburetor: Mikuni BN38
- Rev Limiter: None
- Hull:
- Color: Yellow/White Gelcoat
- Material: SMC
- Upper, front, left side exhaust
- Stock Rear Sponsons
- Fire extinguisher: Rear, right side gunwale, black cap
- No chin pad on hand pole
- Turfed tray with fuel/choke cover
- Siphon bilge
- Finger Throttle
- Pump:
- Mixed flow
- 16* Pitch Aluminum impeller
- Coarse spline, thick driveshaft
- Aluminum wear ring (no liner)
- 1983 JS550 – Cosmetic Updates
- Model Year Changes
- Yellow/white gelcoat is changed to red/white gelcoat
- Graphics changed to a black/silver stripe scheme
- 1984 JS550 – Cosmetic and Safety Updates
- Model Year Changes
- Graphics changed to a blue/silver color scheme
- Black Kawasaki decal running down handpole
- Black chin pad added to handpole
- Pole bracket changed from black to silver
- 1985 JS550 – Cosmetic Updates
- Model Year Changes
- Graphics changed to a silver/light blue/dark blue color scheme
- 1986 JS550 – First Major Update
- Model Year Changes
- Exhaust exit changed to right side below bond line
- Engine ports changed – hp boost
- New pistons with thinner rings
- Exhaust changes to “breadbox” style Jet Power exhaust
- Exhaust bypass fitting visible on left side of hull
- Carb increases to Mikuni BN44 carb with “fuel flood” style rev limiter
- Intake manifold increases to 44mm to accommodate carb
- Flame arrestor changes styling
- Graphics get fresh styling retaining the silver/light blue/dark blue color scheme
- Finger throttle changed to thumb throttle
- Jet pump gets a stainless wear ring
- 1987 JS550 – Cosmetic Updates
- Model Year Changes
- Graphics changed to a blue/white color scheme
- 1988 JS550 – Cosmetic Updates
- 1989 JS550 – Cosmetic Updates
- Model Year Changes
- Red/White Gelcoat is changed to all white gelcoat
- Pole bracket color changed to white
- Graphics changed to a blue/pink scheme
- 1990 550sx – Second Major Update
- Model Year Changes
- Model name gains “SX” suffix
- Driveshaft changes to thinner, fine spline 650/750/800 style
- Pump utilizes smaller, sealed bearings with smaller pump shaft
- Pump cone loses zerk fitting
- Reduction nozzle siphon bilge outlet smoothed
- Aluminum impeller increases to 17.5* pitch
- Bulkhead bearing assembly gets major mass reduction switching to a floating single, sealed bearing (650/750/800 style)
- Bolt pattern on hull bulkhead updated to fit new bulkhead bearing assembly
- Coupler cover changes to plastic and bolts to engine
- Tray pads changed to removable, plastic backed thick rubber
- Hull tray changed to accommodate new tray pads
- Fuel selector/choke door changed to thicker, vinyl covered version
- Graphics changed to a blue/pink scheme
- Siphon bilge line increases in diameter
- Fire extinguisher location changes to left rear gunwale
- Hull gains front and rear thick plastic bumpers (rear covered in rubber)
- Ride plate increases 1” in length
- Straighter handlebars
- 1991-1992 550sx – 3rd and Final Major Update
- Model Year Changes
- Engine changes to an all silver, cylinder reed inducted style engine
- Cylinder studs spaced further apart to accommodate reed blocks and help provide better gasket sealing
- Pistons gain a ring, becoming dual ring pistons
- Switches to a Keihin CDKII 38mm carb
- Introduction of an electronic rev limiter incorporated into CDI
- Steering system gets larger bushings and a slightly quicker turn ratio
- Siphon bilge now bolts directly to hull of ski
- Graphics changed to a blue/pink lightning bolt scheme
- 1993-1995 550sx – Cosmetic Updates, Final Years of the 550
- Model Year Changes
- Graphics changed to a purple/pink scheme
