| MODEL | KTM 640 LC4 SUPERCOMP 1999 |
| Year | 1999 |
| Engine Type | Four stroke, single cylinder, SOHC, 4 valves, engine balancer |
| Displacement / Capacity | 624.6 cc / 38.1 cu in |
| Bore X Stroke | 101 x 78 mm |
| Compression Ratio | 11.5:1 |
| Cooling System | Liquid cooled |
| Max Power | 40.1 kW / 55 hp @ 7000 rpm |
| Max Torque | 55 Nm / 5.6 kgf-m / 40.6 lb-ft @ 5500 rpm |
| Ignition | Kokusan contactless DC-CDI ignition with advanced system |
| Induction | Mikuni BST 40 carburetor |
| Start System | Electric & kick |
| TRANSMISSION SPECS | |
| Lubrication | 2 x Eaton oil pumps |
| Gear Box | 5 speed (1st 14:35 / 2nd 15:24 / 3rd 18:21 / 4th 20:19 / 5th 22:18) |
| Clutch | Multi-disc in oil bath |
| Final Drive | Chain, O-ring 5/8 x 1/4 in (final drive ratio 17:38) |
| CHASSIS SPECS | |
| Frame | Central chrome-moly steel frame |
| Front Suspension | White Power Up Side Down 4357 MXMA fork; 275 mm / 10.8 in travel |
| Rear Suspension | Central WP BAVP3612 shock with PRO-LEVER linkage to swingarm; 300 mm / 11.8 in travel |
| Front Brakes | Single 300 mm disc, 4-piston caliper |
| Rear Brakes | Single 220 mm disc, 1-piston caliper |
| DIMENSION SPECS | |
| Overall Length | — |
| Overall Width | — |
| Overall Height | — |
| Seat Height | 925 mm / 36.4 in |
| Wheelbase | 1510 mm / 59.4 in |
| Ground Clearance | 310 mm / 12.2 in |
| Dry Weight | 149 kg / 328 lbs |
| Wet Weight | — |
| WHEEL SPECS | |
| Front Tyre | 90/90 - 21 |
| Rear Tyre | 130/80 - 18 |
| FUEL SYSTEM | |
| Fuel Capacity | 11 L / 2.9 US gal / 2.3 Imp gal |
| Fuel Consumption | — |
| Top Speed | — |
The 640 LC4 Supercomp is a 1999 competition-oriented enduro model built on KTM's 624.6 cc LC4 single. Compared with the road-biased Adventure and Duke, it uses a longer-travel front fork (275 mm) and a 300 mm front disc with off-road tyres. The source gives only a specification table, so the exact role of the Supercomp badge is not described.
