| 1999 | | | | power |
| Liquid Cooled Engine with Kawasaki Integrated Power | | | | Keihin Power Jet PWK38S Carburetor with K-TRIC |
| Valve System | | | | "Shorty" design places the mainjet and slide closer to |
| KIPS system controls exhaust port height for | | | | the cylinder for improved throttle response |
| increased power and torque | | | | Kawasaki Throttle Responsive Ignition Control |
| Increased flywheel effect helps the rear tire hook up | | | | (K-TRIC) uses a sensor and alter ignition timing |
| The output shaft now has involute splines at the | | | | according to throttle position and engine speed for |
| countershaft sprocket for less play, quicker | | | | better throttle response and more power |
| acceleration and increased durability | | | | Revised Power Jet system uses an electronic |
| Keihin Power Jet PWK38S Carburetor with K-TRIC | | | | solenoid to close a fuel passageway at two separate |
| New "shorty" design places the mainjet closer to the | | | | rpm settings to extend the power peak and increase |
| cylinder for improved throttle response | | | | top-end power at over-rev |
| Kawasaki Throttle Responsive Ignition Control | | | | UNI-TRAK Rear Suspension |
| (K-TRIC) uses a sensor and alter ignition timing | | | | Cast aluminum section is redesigned for less unsprung |
| according to throttle position and engine speed for | | | | weight and more rigidity |
| better throttle response and more power | | | | The shock now features both low- and high-speed |
| Power jet system uses an electronic solenoid to close | | | | compression damping adjustments |
| a fuel passageway at high rpm to extend the power | | | | Aluminum shock components reduce unsprung weight |
| peak and increase top-end power at over-rev | | | | Triple-rate shock spring makes shock action even |
| Airbox and boot | | | | more progressive |
| New airbox and stiffer connecting boot improve | | | | 48 mm Upside Down Cartridge Fork |
| airflow around the shock to improve top-end power | | | | New bladder system helps smooth out jolts and |
| UNI-TRAK Rear Suspension | | | | control bottoming |
| Cast aluminum section is redesigned for less unsprung | | | | New .43 kg/mm fork springs |
| weight and more rigidity | | | | Polished internal surfaces for smooth action |
| Redesigned needle bearings and sleeves reduce | | | | New piston assembly on the cartridge is speed |
| unsprung weight and prevent incorrect assembly that | | | | sensitive |
| can cause them to bind | | | | Front and Rear Disc Brakes |
| The shock now features both low- and high-speed | | | | Redesigned front brake caliper for better feel |
| compression damping adjustments | | | | Improved dust seals at the rear brake lever and caliper |
| The shock oil seal head assembly and adjuster cap | | | | High Tensile Steel Perimeter Frame |
| changed to aluminum and the aluminum shock clevis is | | | | Compact and quick handling |
| now lighter to reduce unsprung weight | | | | Removable aluminum rear sub-frame for easy access |
| New triple-rate shock spring improves suspension | | | | to the rear shock |
| action at full compression | | | | Detail Changes |
| 46 mm Upside Down Cartridge Fork | | | | New graphics |
| New aluminum upper fork tubes are smaller in | | | | Flat seat allows free rider movement |
| diameter at the upper clamping area (54 mm to 52 | | | | New handlebar bend for increased rider comfort |
| mm) for a plusher ride and less weight | | | | 2001 |
| Stronger inner and outer fork tubes have more | | | | First gear ratio changed and flywheel weight changed |
| overlap to improve suspension action, especially on | | | | for better throttle response and acceleration |
| "slap-down" landings | | | | 2002 |
| New rubber bottoming damper and 10 mm longer fork | | | | Higher Compression Ratio, Beefier 48mm forks,new |
| bottoming cone reduce bottoming | | | | twinspark ignition system, new 2 piece KIPS |
| New fork leg lowers with two-bolt axle clamps | | | | powervalve, and revalved rear shock. |
| increase front end rigidity | | | | 2003 |
| Several internal components changed to aluminum | | | | Fuel Mixes, from 30:1, to 40:1 or 52.5:1 |
| Front and Rear Disc Brakes | | | | 2004 |
| New ceramic coating on backing of rear brake pads | | | | 2005 |
| insulate them from heat | | | | Even Suspension Layout |
| Backing plates now thicker to prevent warping under | | | | Larger Fuel Tank |
| extreme conditions | | | | Larger Radiator |
| High Tensile Steel Perimeter Frame | | | | Internal Spark Arrestor |
| Upper frame rails lowered slightly to lower fuel tank | | | | Oppositional Combustion Chamber Layout |
| and provide flatter seating position | | | | Third Gear Ratio Moved Up 0.012 Degrees |
| New aluminum rear sub-frame | | | | Combustion Rate Improved |
| Detail Changes | | | | Leading Fuel Line Made 2 mm Wider for Enhanced |
| New graphics and restyled rear fender and radiator | | | | Riding Capabilities |
| shrouds | | | | Angled Piston Improves Horsepower by 2HP |
| Flatter seat allows freer rider movement | | | | Riding Position Lowered for Easy Handling |
| New handgrips offer better feel | | | | King Hart Racing Chain is Stock |
| Rerouted clutch cable for easier pullby: naudia | | | | Wobbling at High Speeds is Reduced By Carefully |
| vengeace from commerce Texas | | | | Shaped Air-Intake Ports |
| 2000 | | | | An Extra large aftermarket Spark Plug is Stock |
| Liquid Cooled Engine with Kawasaki Integrated Power | | | | Spark Arrestor 1.2 mm Wider |
| Valve System | | | | Heat Proof Radiator Tubes Increase Performance |
| Revised porting for increased low-end and mid-range | | | | Entire Exhaust System polished on inside for Lower |
| power | | | | fuel consumption |
| Revised KIPS system controls exhaust port height for | | | | Radiator Capacity has Increased From 800mls to |
| increased power and torque | | | | 1030mls. |
| KIPS governor bearing size is larger for increased | | | | Evolved Piston head shape Increases displacement by |
| durability | | | | 4cc |
| Electrofusion cylinder | | | | 0.25 Litre Engine enhanced by stronger fuel Jets |
| Improves heat transfer for consistent power output | | | | 8 Litre Fuel tank is increased to 8.5 Litres |
| It is porous so it holds lubrication well | | | | 2006 |
| It is hard so it resists abrasion and seizure | | | | Renthal aluminum handlebars. |
| Allows closer piston-to-cylinder clearances for more | | | | New piston profile and muffler design. |