KTM 500 K4
KTM 500 K4 | |
Manufacturer | |
---|---|
Production | 1982 - 85 |
Engine | Single cylinder, four stroke SOHC, 4 valves |
Compression ratio | 9.8:1 |
Top Speed | 143 km/h / 89 mph |
Transmission | 5 Speed |
Suspension | Front: Telescopic leading axial fork Rear: Swing arm, single shock |
Brakes | Front: 230 mm Disc Rear: 180 mm Drum |
Front Tire | 3.00 - 21 |
Rear Tire | 4.50 - 18 |
Weight | 144 kg / 317 lbs (dry), 156 kg / 344 lbs (wet) |
Fuel Capacity | 9 L / 2.4 US gal / 2.0 Imp gal |
Manuals | Service Manual |
It could reach a top speed of 143 km/h / 89 mph.
Engine[edit | edit source]
The engine was a Air cooled cooled Single cylinder, four stroke SOHC, 4 valves. The engine featured a 9.8:1 compression ratio.
Chassis[edit | edit source]
It came with a 3.00 - 21 front tire and a 4.50 - 18 rear tire. Stopping was achieved via 230 mm Disc in the front and a 180 mm Drum in the rear. The front suspension was a Telescopic leading axial fork while the rear was equipped with a Swing arm, single shock. The 500 K4 was fitted with a 9 L / 2.4 US gal / 2.0 Imp gal fuel tank. The bike weighed just 144 kg / 317 lbs.
Photos[edit | edit source]
Overview[edit | edit source]
KTM 500 K4
Road Test Which Bike 1982
KTM have made a name for
themselves in the large capacity bike field for their tough and powerful
racers. But up till now their machines have been exclusively two-stroke. The
introduction of a 500cc four-stroke is, therefore a bit of an unknown
venture for them. It proved an unknown venture for this tester too.
The KTM's motor is made by
Rotax, and can also be found in SWMs and Can Am/ Armstrong. This particular
lump is 504cc with an 89 x 81mm bore and stroke, but there are 493cc and
562cc versions. It uses a four-valve head with the single cam belt driven
off the left side of the crank. The Nippondenso capacitor discharge ignition
comes off the other side. A 34mm Bing carb supplies the juice. Lubrication
is dry sump with oil in the frame and a double-trochoid pump is used for
circulation. Primary gears and a wet clutch take the power to the five-speed
box.
The bike we had a chance to test was collected from the factory in Austria
by Dave Jeremiah and ridden in that round of the European Enduro
championship. Back in England, we picked it up from H. Cecil Motorcycles of
Ledbury, who keep it fettled for him. Ace motocross rider Dave Tomasik had
volunteered to camp it up in front of the cameras for the day on his
favourite practice ground. This turned out to be a small
bottom. The going was basically hard but with a couple of inches of slippery
on top due to overnight rain. Dave was flying around, whilst our trusty
lensman Tim and I were walking around observing the action and choosing good
spots for the pics. "Sorry Dave, can you ride that bit again? Only get the
bike completely off the ground this time."
Dave and Tim were working well
together. I was admiring the sun dancing on the summer bracken, thinking
that it was days like this which make life worthwhile, when I realised the
bloody racket in the background was something I hadn't heard since the bad
old days when people like Arthur Browning and Vic Eastwood used to be on
telly every Saturday afternoon. Some of the reason for this noise was the
nonstandard silencer fitted to the bike. The original item was an enormous
steel contraption which wouldn't have been out of place on a Japanese trail
bike. Apart from being a weight penalty it didn't do too much for the
performance either.
Starting the KTM is rather like the old XT500 Yamaha. There's a window in
the cam drive belt cover and you can turn the engine over with the aid of a
pressor till the white spot appears and then hoof it over. It doesn't always
work but you've got a better chance the harder you kick. As I was trying to
kick it over on a somewhat off-camber bit of ground with little success, I
decided to aim the bike down the hill and try a bump start. The rear wheel
locked in second and third and by the time I'd found fourth I'd run out of
hill. By this time I was feeling a bit of a prat. I eventually got going
with the help of Dave's size 10 Alpine Star.
So there I was in this stream
bed with nowhere to go on a bike I'd never ridden before. Maybe it wasn't
going to be one of those days that make life worthwhile after all. Anyway, I
stuffed it into first, eased out the clutch, stood on the pegs and started
to pick my way up the hill to try and rejoin the course. First gear runs out
of steam so it's into second. Too much throttle produces monster wheelspin
in these conditions so I back off, toq much, and the bugger stalls. I am now
in danger of suffering a serious loss of credibility, not to mention falling
off the bike which is leaning at a crazy angle away from me. Bike and rider
reach the bottom of the hill once more, a few feet apart. It's time to get
violent. The engine starts as I try to snap the kick start shaft in two. Not
wanting to be caught out again, I stab it into second straight off and dump
the clutch. Wheelspin halfway up the hill, grab third and phew! made
it. At the top of the hill I give Dave a look signifying that I've walked
out of the house without my trousers and he says; "Funny that, Andy Roberton
came up here last week and he couldn't get round either." As he is the
current leader of the British Enduro Championship, that made me feel a lot
better.
We move on to a different piece of ground where 1 can get some feel of the
bike. Race up a few tracks and get a bit sideways. The power on the KTM is
much more basic than anything you'll find in Japanese motors even though
it's fitted with a single balance shaft, you can still feel every power
stroke. It comes on very strong at the bottom of the rev range, goes a bit
flat mid-range then comes back in till the motor revs out. The top-end power
makes this motor different: most big singles run out of pulling power well
before they run out of revs. Like most four strokes, the KTM motor doesn't
like sudden big handfuls of gas it will either do nothing or cough
severely and if the revs drop too low it will stall without warning. Apart
from these points the motor will do anything asked of it. The front won't
lift very easily on its own so a certain amount of pilot muscle has to be
employed. This is particularly noticeable on downhills which can turn into a
helter skelter run with the front wheel bouncing off everything.
For the first time, we've come
across a disc brake on a proper dirt bike and I must say it's impressive.
It's very strong but never caught me out. The single-piston Brembo caliper
works on what appears to be a stainless steel disc; anyway, it isn't prone
to rust. It is quite possible to come to a stop on wet grass using the front
brake only, without falling off. This bike takes a long time to get used to,
particularly if you're more familiar with two strokes. It took me about half
a day. Different power characteristics need different techniques. The bike
is very predictable on dry or loose going but I never never felt in control
of the front end in wet conditions. The front end uses a 38mm Marzocchi fork
which some might think on the petite side but there wasn't any noticeable
flex. The back employs KTM's irreproachable single-shock Pro-lever set up
and, even though it was set soft, didn't cause any problems. It gets the
grip dwon too - on fast climbs with the rider's weight forward the rear
wheel can be left to its own devices, which ensures continuous traction.
A lunchtime break at the local
boozer gave me a chance to try the bike's road performance. This was an
opportunity to appreciate the true meaning of tractability: top gear will
pull cleanly from 15mph through to a maximum in excess of 95mph (according
to the speedo in Dave's Cortina the one on the bike runs out at 65.) At
high speeds the bars tingle some, but the motor feels sweet enough and it
handles. Also at these speeds the disc brake gives you the confident edge.
Gear shifting is very smooth in any direction, the only criticism being the
over large gap between first and second.
Now comes the crunch. If you're
interested in this type of tackle for competition use, you're going to have
to part with 1899 greenies. If you want the ultimate poser's trail bike it's
going to be £2079 with taxes paid. But at least you can be assured of a
certain amount of exclusivity for your money. There won't be many around.
Source Which Bike 1982
Make Model | KTM 500 K4 |
---|---|
Year | 1982 - 85 |
Engine Type | Single cylinder, four stroke SOHC, 4 valves |
Displacement | 504 cc / 30.8 cu in |
Bore X Stroke | 89 x 81 mm |
Compression | 9.8:1 |
Cooling System | Air cooled |
Induction | 34mm Bing carburetor |
Starting | Kick |
Max Power | 28 kW / 38 hp @ 7600 rpm |
Transmission | 5 Speed |
Final Drive | Chain |
Front Suspension | Telescopic leading axial fork |
Rear Suspension | Swing arm, single shock |
Front Brakes | 230 mm Disc |
Rear Brakes | 180 mm Drum |
Front Tire | 3.00 - 21 |
Rear Tire | 4.50 - 18 |
Dry Weight | 144 kg / 317 lbs |
Wet Weight | 156 kg / 344 lbs |
Fuel Capacity | 9 L / 2.4 US gal / 2.0 Imp gal |
Top Speed | 143 km/h / 89 mph |