KTM 640 LC4 Enduro


Make Model

KTM 640 LC4 Enduro


2003 - 04


Four stroke, single Cylinder. SOHC, 4 valves, engine balancer


624.6 cc / 38.1 cu in
Bore x Stroke 101 x 78 mm
Compression Ratio 11.5:1
Cooling System Liquid cooled
Lubrication 2 x Eaten oil pumps


Mikuni BST 40 carburetor


Kokusan contactless DC-CDI ignition with advanced system


Electric & kick

Spark Plug



12V 8Ah, maintenance free

Max Power

40.1 kW / 55 hp @ 7000 rpm

Max Torque

55 Nm / 5.6 kgf-m / 40.6 lb-ft @ 5500 rpm


Multi-disc in oil bath


5 Speed

Primary Drive Ratio

30:81, straight cut gears

Gear Ratios

1st 14:35 / 2nd 15:24 / 3rd 18:21 / 4th 20:19 / 5th 22:18

Final Drive Ratio


Final Drive

Chain, O-ring 5/8 x 1/4"


Central chrome-moly steel frame

Front Suspension

White Power – Up Side Down 4357 MXMA fork

Front Wheel Travel

280 mm / 11.0 in

Rear Suspension

Central shock absorber (WP BAVP3612) with PRO-LEVER linkage to rear- swing-arm with needle bearing

Rear Wheel Travel

320 mm / 12.6 in

Front Brakes

Single 300 mm disc, 4 piston caliper

Rear Brakes

Single 220 mm disc, 1 piston caliper

Front Tyre

90/90 - 21

Rear Tyre

140/80 - 18

Steering Head Angle



1510 mm / 59.4 in

Ground Clearance

310mm / 12.2 in

Seat Height

930 mm / 36.6 in

Wet Weight

158 kg / 348 lbs


350 / 773 lbs

Engine Oil Capacity 

2.1 L / 2.2 US qt / 1.8 Imp qt

Fuel Capacity 

12 L / 3.2 US gal / 2.6 Imp gal

Consumption Average

4.7 sec

Top Speed

168 km/h / 104 mph

I'm coming up to the 10 000 km mark on the Katoom now, so it's probably time to post a review. This is the most versatile and most funnest bike I have ever owned. The bike has been totally stock until recently.

The KTM LC4 (Liquid Cooled, 4 valve) dates from around 1987, replacing the earlier air cooled KTM 600. It has gained quite a few refinements over the years, among other things; electric start, counterbalancers off the crank & camshaft, A major makeover in '99, 43mm USD forks in '02,and new for '03 a 'high flow' head and hydraulic clutch. The '04 & '05 are the same apart from a stronger clutch AFAIK. The specs are here

The Bike
My 1st impression of this machine was how much it looked like a modern dirt bike. The big USD forks, the beefy Magura fat bars, the seat extending right over the tank & the styling of the orange plastic all mean that the 640 doesn't really stand out when parked in a lineup of KTM's MX & Enduro models.
Throw a leg over the thing though and it is apparent this is a different beast - it's much heavier at 149 kg, and the seat is not a vinyl covered 4x2.

Start the bike and you're greeted with a quieter than expected exhaust note from the big steel silencer, she's fitted with a kick starter for a backup which works OK but usually I'm lazy & use the button.

Out on to the the road and you'll notice the vibration. The LC4's are notorious for it. However as my bike has run in it has got far smoother & I have probably gotten used to it a bit. I feel less vibes from it now than I did on my old VFR400. On the open road up to about 120 is smooth & comfortable, over this the wind & the vibes combine to remind you what a dastardly criminal you are being.You'll see around 160 km/h tapped out on the straights.

When the curves come up the fun begins. The 300mm disc & Brembo caliper on the front do well slowing down, careful on the down changes 'else the rear will be chirping & skittering around, especially on the stock semi knobblies. The big travel forks & 21 front hoop don't give the feel of a sportbike, but seem to hang on well. At the apex give the bitch a handful & hang on - the very good WP rear shock & the big single power delivery give awesome drive & traction, seemingly oblivious to any lumpy tarseal as you exit the corner. This thing is a total blast on twisty tarmac, the tighter the better.

It's fairly comfortable too, I think nothing of going for a 600km road ride, however I would like to try the wider, softer seat KTM make, and maybe one day I'll make a bit of a windscreen to take the load off my arms as you do have to pull yerself into the bars a little bit at highway speeds.

Review: Clint, Kiwibiker, October 2004