Kawasaki KL 250

Based on the Honda SL/XL250 concept of a dual-purpose lightweight, the KL appeared in the early months of 1978. Like the Honda a 250 four-stroke single, it showed advances commensurate with its later design, chiefly in the matter of less weight and more effective suspension. It was, in fact, Kawasaki's first attempt at producing a dual-purpose bike, though much of its specification was based on machinery that was far from new — principally the KZ200 road single.

Two large valves (36mm for the inlet, 30mm exhaust) were operated by a single camshaft running directly in the light-alloy cylinder head. Barrel and head were retained by long through-bolts into a vertically split crankcase, the latter striking a new note in Japanese engineering, which ordinarily favoured horizontal jointing. The pressed-up crankshaft ran on

roller and ball bearings, with a caged roller bearing for the connecting-rod big-end.

Vibratory but powerful, the KL's engine put out 17.5 bhp at 8,000 rpm, sufficient for 60mph cruising by road and giving plenty of power in not-too-demanding crosscountry work.

Motorcycle reveiw 1978

SAMMY MILLER RIDES AND COMMENTS ON THE KL250 — KAWASAKI'S NEW FOUR-STROKE SINGLE FOR THE ROUGH RIDER . . .

HAVING seen Sammy Miller put the Kawasaki KL250 through its paces over the ten acre patch of ground he uses for trials practice down in Hampshire, it was easy to understand why he has achieved so much in the world of trials riding.
No way was he going to give best to a mere 250cc trail bike. He put the latest Kawasaki four-stroke trailster through the most arduous test that would be encountered by genuine off-road trials machines and surprisingly, it almost passed with flying colours.

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Let's face it, no motorcycle, about the Kawasaki's trials motorcycle, can be expected to drop down a steep bank into a river bed, wade through a stream and climb up a slippery muddy slope out of its predicament. With a little bit of footslogging from the long, gangling Miller legs, the Kawasaki achieved the nigh impossible. The electrics remained watertight, the carbu-ration stayed clean and, in spite of mediocre ground clearance under the circumstances, the motor slogged its way to firmer ground.

Next came a series of concrete 'steps' kindly provided by a local contractor who had dumped two or three mounds of ex-council roadworks on the Miller testing ground.

With a twitch of the throttle, Sammy lifted the front wheel of the KL250 overthe first obstacle and then proceeded to skip from one block of concrete to another with surprising ease. The suspension dipped and bounced, while the rear wheel spun and fought for grip.

Cresting the mound of rubble, Sammy turned the machine on to a stretch of dumped topsoil which appeared from twelve feet below like a miniature hill range of peaks and troughs with precipitous drops on either side to disaster.

The Miller riding technique was displayed to the full as he demonstrated complete throttle control coupled with perfect balance. If we asked for a wheelie, Sammy did the necessary for photographs ... if only the weather had been suitable to catch the maestro in action!

Unfortunately, because of poor photographic conditions, it is only possible to describe the incredible way in which Sammy tested the kWacker to its limit.

A further demonstration of rough riding through the woods, followed by broadslides on loose, sandy soil completed the testing as seen through the eyes of one of the best off-road motorcycle development riders in the world.

In slightly under half-an-hour, Sammy had made his mind up the Kawasaki's capabilities as a serious off-road trail bike. We waited in anticipation of his decision . . . was it a heap or a machine to be taken in earnest by an enthusiastic green roads rider?

"It's surprising," said Sammy as he dismounted from the mud-bespattered machine. "It's pretty good." 

"There's no way it can be seriously considered as trials bike because it's too heavy and trimmings such as flashing indicators are completely unnecessary and a hindrance for off-road riding."

We noticed that one of the rear indicators was dangling aimlessly on its lead wire, having broken off on its brief encounter with a tree in the woods.
"What about the suspension?", we asked.
"Oh, that was pretty good," Sammy replied. "It didn't bottom out at the front or rear and the damping is surprisingly controlled."
"The only problem encountered on the deeper potholes and ruts was lack of ground clearance. The exhaust system and frame are adequately protected but the seven or eight inches clearance isn't sufficient for real rough riding. Also, the footrests are too low and tended to catch too easily on the edge of the deeper ruts."

What about the engine and gearing of the machine? We noticed that you were having to travel fairly fast through some of the sections to keep the engine on the boil.

"Well, yes. I did have to ride a little faster than I normally would on a genuine trials bike. But this is because the first and second gears on the Kawasaki are a little on the high side for some of the ground I was trying to cover," replied Sammy.
"For complete off-road use, I'd probably change the rear wheel sprocket and add a few more teeth.
"Mind you, I was pleased with the motor and the way in which it responded to the throttle. There were no flat spots on carburation and it had a very wide and useful power band from about 3000 rpm up to maximum.
"Also, it didn't stall too easily and kept pulling well at low revs," said Sammy. "Going back to the gearing, I noticed that in spite of being too high, the first three gears were fairly close for off-road riding with fourth and fifth well-spaced for using on the road. It seemed a pretty good compromise to me."

Did Sammy think it would make a serious enduro bike?
"Well, I reckon it would if you removed some of the ancillaries like the flashing indicators and lost some of the weight. Mind you, it definitely feels a bit lighter than the XL250 Honda."

What about the riding position?
"Pretty tall in the saddle for a small person," smiled Sammy. "But there was a good relationship between the seat and handlebars. It felt very controllable on the rough although, as I have mentioned, the footrests were on the low side."

Any other comments?
"Not really," replied Sammy. "As I've said, the motor's responsive, the bike is well balanced and the suspension is good. There's not a great deal to fault and I think that overall it's quite a neat package."

ON THE ROAD
After Sammy had finished playing with the machine on the rough, it returned to general duties on the road. A trip up the A33 to Chobham allowed us to obtain performance figures on the test track and after a fortnight of on-road riding we were able to assess the machine's capabilities as a road runner.

The long travel suspension gave a comfortable ride over all road surfaces and, in spite of the knobbly tyres, the roadholding was fair to average with a slight tendency to drop into corners or oversteer slightly.

Starting hot or cold was a first or second prod on the kickstart.  No electric start is fitted.
The controls were all light and smooth in operation, with the clutch taking up the drive without any judder or snatch.

Although Sammy commented on the fact that the lower gears were somewhat high for rough riding, we found that for road use it was unnecessary to use first gear to start off and unless on a steep hill, second gear was perfectly suitable for moving off from a standstill.

Third, fourth and fifth gears were widely spaced and, if anything, the KL250 was overgeared in the top ratio, which stopped the motor being revved to its limit and gave a happy cruising speed of around the legal 70mph. From 2000 to 4000rpm, the motor slogged like a typical four-stroke single with every firing stroke pulsating through the machine.

The mill really started to get into its stride above 4000rpm, with slight vibration setting in at about 6000rpm. However, it was far from bulb blowing or knuckle shattering as on some vertical twins and as the revs soared towards the 9000 red line limit, the power simply kept pouring in.
Carburation was clean right through the rev range with no flat spots or hesitation. Response to the throttle was instant.

Braking on the Kawasaki trailster wasn't spectacular but definitely adequate. In dry or wet conditions, the front and rear drums performed well without grabbing or fading due to heat or ingress of water.

Surprisingly, the rear drum is larger in diameter than the front and this is possibly the reason why the back wheel could be made to lock up under heavy application. But both brakes were progressive in operation and one had to be extremely ham-fisted or footed to make them react violently.

Apart from the wide bars, the riding position on the KL250 was almost ideal for about-town use with perfect control at traffic trickling pace. Solo the deep dualseat was comfortable, but although the bike is fitted with pillion rests, two-up riding was decidedly cramped.

Electrically, the Kawasaki is fairly basic with its flywheel magneto/coil ignition system and a six-volt trickle charge to a 6ah battery, which feeds the horn, flashing indicators, and stop light.
The main lighting is direct and , the 35/35W bulb on dipped and main beam is satisfactory for the performance of this dual-purpose motorcycle.

Overall, when compared with its contemporaries in the 250cc trail bike category, the Kawasaki KL250 must be considered among the best in the range. At £679 including VAT it is slightly more expensive than its two-stroke competitors, but if you're a four-stroke fan and an off-road freak, then the KL250 is well worth considering as your fun bike.

Charles Deane

1 The five-position spring loading on the rear suspension leg gives smooth, controlled damping at the rear swinging arm.
2 Sammy Miller praised the two-way damped front forks for their long travel and rough riding capability without bottoming out.
3 Simple instrumentation shows a 9,000rpm limit on the rev counter beam, with warning lights for trafficators, neutral and main
4 The single-overhead-camshaft motor proved flexible and well-suited to its task, although the gear ratios were high for off-road.
5 Mick Grant, Kawasaki's road racing ace, also enjoyed a spin on the rough with the new KL250 four-stroke trail blazer . . .