Ktm 600 Lc4
CYCLE WORLD TEST
KTM 600 LC4
Austrian Heavy Metal
IN SHOW BUSINESS, THERE'S A SCHOOL OF THOUGHT that says you've got to make them wait, otherwise they won't appreciate you. But the flip side of that coin says that the longer you keep them waiting, the more they expect.
KTM apparently believes in the first part of that philosophy. It was in the fall of 1984 when Cycle World first saw KTM's promising new LC4 600 four-stroke engine under development in Austria. At the time, it seemed likely to be the lightest, most powerful four-stroke dirt-bike engine ever sold. And the word back then was that the engine would make its debut in a 1986 model.
Well, 1986 has come and gone, and only now is the LC 4 making its way to this country. And all that time spent waiting has made for some pretty high expectations.
At first glimpse, at least, the 600 enduro is no disappointment. In the KTM tradition, the bike is beautifully finished with tidy welds, lots of aluminum, disc brakes at both ends, and the latest in White Power suspension. But probing deeper turns excitement into disappointment; the liquid-cooled 600 is a maze of wiring looms, electrical gadgets, unused frame bracketry, vent hoses, external oil lines and even a rear brake-light switch. Certainly not your basic, simple, four-stroke enduro Single.
In that respect, the 600 looks for all the world like a street-legal dual-purpose bike without turn signals and street instruments. And for the most part, that’s exactly what it is. In Europe, the 600 is a street/dirt model aimed directly at the lucrative dual-purpose market. But somewhere between Europe and America, the KTM changed course, and now it’s basically a dual-purpose bike that isn’t street-legal in this country.
Further evidence of the 600’s dual-purpose origins can be found in its weight; 280 pounds without gasoline. That’s 10 pounds heavier than Honda’s newest XR600R, a bike not renowned for its lightness, and nearly 30 pounds more than a Husky 510 four-stroke Single.
Not only that, KTM made numerous other concessions to ofif-road lightness to ensure adequate reliability on the street. The 600 has an oil pump (Husky’s 510 uses only splash-type lubrication) that provides pressure-fed lubrication to the main bearings and top-end components. There’s also a large paper oil filter, two small steel oil filters, an electric coolant pump, and a red light on the handlebar that illuminates if the engine overheats. And although the 600 has a wet-sump oiling system, the frame’s front downtube serves as an additional reservoir to increase oil capacity.
Reliability-conscious KTM also thought that piston life would be too short with a full-slipper racing piston like that used in the Husky 510, so KTM’s engineers designed and patented their own piston. The short, full-skirt piston differs from a conventional design by being wider in its middle rather than at the skirt. According to KTM, this reduces piston noise and increases its life. The piston uses a one-piece oil ring, again, for longer life and an ability to withstand heat better than a three-piece ring.
All of these design features give this same basic 600 the potential to be something other than just an off-road-only machine. In fact, KTM America is currently working on a street-legal dual-purpose 600 for the U.S. market.
In performance terms, though, the sohc, four-valve engine has not been compromised at all, for it has impressive power and an excellent powerband for any type of riding. The power output is comparable to that of the ’88 XR600R: smooth, responsive and fast at all engine speeds. It is marginally slower than an XR only in the middle and upper rpm ranges.
The acceleration was slightly hampered by the gearbox, which has a horrendous ratio jump between first and second. But, according to KTM, the early 600s are fitted with a European gearbox, whereas later U.S. models will have revised ratios. Otherwise, top gear allows sufficient speed on fast roads, and first gear is low enough for any trail condition. And although the five-speed gearbox shifted a little notchy, we never missed any shifts.
We also never missed an opportunity to slide the 600 on a fireroad, something this bike does very well. All it asks is that its rider sit as far forward as possible in turns to keep
the light front end from skating. If the rider complies, the Metzeler front tire grips well as the rear moves smoothly out into slide mode. But if the rider sits too far rearward, the front end will skate and make the bike run wide.
Front-tire skate isn’t as obvious when the 600 is ridden on narrow trails, but the bike still responds best to an aggressive, forward riding position. Nevertheless, it can be ridden amazingly fast on tight trails, despite its weight and long wheelbase. Not surprisingly, however, it feels a little top-heavy, and its sheer bulk can prove tiring, factors that make the 600 less than ideal for serious enduro competition.
It is well-suited for all-around trail use, though, with suspension damping and spring rates that do a lot to increase the bike’s fun factor. The White Power suspension units at both ends of the 600 perform smoothly and controllably at any speed up to a racing level, at which point the spring rates are a little too soft. But the suspension is near-perfect for the bike’s intended general use.
Suprisingly, the KTM works fairly well in the fast, wideopen expanses of the desert. It’s certainly not a fullfledged desert racer, but it still can be ridden quite fast. At high speeds, its plush suspension will bottom too often, but the bike remains stable, at speed and even in deep sand.
High speeds don’t pose a problem when it’s time to stop, either; the disc brakes bring the bike to a halt very nicely. The front disc is not particularly powerful, requiring a rather hearty pull at higher speeds, but it never fades, even during near-constant use.
But while our test bike always stopped predictably, it often proved nearly impossible to start. Sometimes it would fire on the first few kicks, other times it would take a seemingly endless number of healthy stomps. Fiddling with the jetting, the ignition timing and the valve settings yielded a minor improvement, but the starting never was up to par.
That wasn’t the only problem our test bike suffered. The fuel filter located inside the fuel tank came adrift and let crud get into the carburetor jets, which caused the engine to die suddenly a few times before we figured out what was happening. An accessory in-line gasoline filter cured the ailment.
We also had a problem with the kickstart lever, which would move outward on its shaft and contact the shift lever. This sometimes caused the bike to jump into gear while being kickstarted. We ground some metal off the kick lever, which helped for awhile, but the problem surfaced again. And the 600 left in its wake an assortment of small, broken parts such as pipe mounts, a frame lug, even the rear sprocket. Annoying and a bit much, even for a first-year model.
On the positive side, the 600’s seat is very comfortable on long rides; the 2.3-gallon gas tank is nicely shaped and out of the rider’s way; and the aluminum handlebar is strong and has an intelligent bend. Plus, the 600 has numerous small conveniences, including a handlebarmounted choke lever, an easy-to-pull and seemingly sturdy clutch, and a light throttle action.
At $4399, the KTM costs $600 less than a Husqvarna 5 10, but is no match for the Husky as a competition bike. The KTM is a good matchup for a Honda XR600R, however, despite costing $ 1 100 more; and by the time an XR owner replaces his bike’s fork and shock with suspension units comparable to the KTM’s, there won’t be much difference in price—and a stock KTM will still handle better.
So, despite its numerous flaws, the KTM 600 has a lot going for it. It’s quite good in most respects right now, in its very first year, and it will only get better as time goes on.
It’s just a matter of a little more waiting. And we already know how to do that.
KTM 600
$4399
