| MODEL | YAMAHA YZF 600R THUNDERCAT 2003 - 2004 |
| Year | 2003 - 2004 |
| Engine Type | Four stroke, transverse four cylinder, DOHC, 4 valves per cylinder |
| Displacement / Capacity | 599 cc / 36.5 cu in |
| Bore X Stroke | 62 x 49.6 mm |
| Compression Ratio | 12.0:1 |
| Cooling System | Liquid cooled |
| Max Power | 72.9 kW / 100 hp @ 11500 rpm (67.9 kW / 91.0 hp at the rear wheel) |
| Max Torque | 65.7 Nm / 6.7 kgf-m / 48.7 lb-ft @ 9500 rpm |
| Ignition | Digital TCI |
| Induction | 4 x 36 mm Keihin CV downdraft carburetors |
| Start System | Electric |
| TRANSMISSION SPECS | |
| Lubrication | — |
| Gear Box | 6 Speed |
| Clutch | — |
| Final Drive | 530 O-ring chain, 15 front / 47 rear teeth |
| CHASSIS SPECS | |
| Frame | Twin spar, steel, delta box |
| Front Suspension | 41 mm telescopic fork, adjustable preload, compression and rebound damping; 130 mm / 5.1 in travel |
| Rear Suspension | Monoshock, adjustable preload, bump and rebound; 120 mm / 4.7 in travel |
| Front Brakes | 2 x 300 mm discs, 4 piston calipers |
| Rear Brakes | Single 245 mm disc, 2 piston caliper |
| DIMENSION SPECS | |
| Overall Length | 2060 mm / 81.1 in |
| Overall Width | 754 mm / 29.6 in |
| Overall Height | 1190 mm / 46.8 in |
| Seat Height | 810 mm / 31.7 in |
| Wheelbase | 1415 mm / 55.7 in |
| Ground Clearance | 135 mm / 5.3 in |
| Dry Weight | 189 kg / 417 lb |
| Wet Weight | 210 kg / 463 lb |
| WHEEL SPECS | |
| Front Tyre | 120/60-17 |
| Rear Tyre | 160/60-17 |
| FUEL SYSTEM | |
| Fuel Capacity | 19 Litres / 5.0 US gal / 4.2 Imp gal |
| Fuel Consumption | 6.1 L/100 km / 16.4 km/l / 38.6 US mpg |
| Top Speed | 246.8 km/h / 153.3 mph |
For 2003 and 2004 the Thundercat was sold as a balanced middleweight for commuting as well as track days, with a plusher seat, slightly rear-set pegs and a taller screen. The liquid-cooled slant-block four uses ram-air induction and a 4-2-1 exhaust, and the frame uses the engine as a stressed member. Yamaha stated it was not meant for novice riders.
