1974 KX250 Cycle World Test

POKER, IF YOU don’t already know, is a game of both patience and action. Players are dealt cards, and play them out, bidding according to their value and the odds of someone else having something better. Poker is also a game that should  be familiar to just about every motorcyclist.

As a motorcyclist, and therefore always a potential purchaser, you are dealt a new hand each year, by the motorcycle manufacturers, in the form of new and (hopefully) better models. This is true whether you are a street biker buyer or an off-roader.

The Japanese are the most notorious for dealing out fancy hands. The Europeans change little, if anything, from year to year. but the Big Four? WOW!

kx250
This year, after sitting out several hands of  motocrosser, motocrosser, who`s got the best motocrosser?, Kawasaki has pulled up a  chair. They want “in” for 1974. And in they are with the KX250.

Although Kawasaki has produced a 250 motocrosser before it was only a modified F-11 enduro bike, which was manufactured in limited quantity to qualify their special works bikes for AMA motocross. The old F-11M had a double-cradle frame, good suspension, a bad rear brake, and a host of other items both acceptable and regrettable. These few limited production machines were also released for road tests to the magazines, top flight kibitzers that we are.

Kawasaki realized that the press can indeed be instrumental in not only introducing new machinery to the public, but also in helping to sell that machinery. The first few bikes were given to us to see just what we would complain about and what we would praise. They were guinea pigs. The KX250 is the sum of what Kawasaki knows about motocross, and what the magazines think they know. Modesty aside, it tumed out to be a pretty good package.

kx250_2

The KX250’s frame is a new single-downtube item with a hefty gusset at the steering head. ‘The Frame splits conventionally just below the forward motor mount and cradles the engine with two case-protecting undertubes. The entire frame is made from what is referred to as Japanese chrome moly. While this steel cannot meet the high standards of the Swedish chrome moly used in Husqvarna frames, it is much stronger and lighter than the mild steel used on many other bikes.

This piston-port Single is specially designed for motocross. Where the F-11M had a square bore and stroke of 68mm, the KX sports a bore of 69.5mm and a shorten stroke measuring 64.9mm. This reduces piston speed at any given rpm and allows the engine to rev higher.

Power delivery through a wet, mult-disc clutch and straight-cut primaries is a five-speed transmission with very tightly-spared gears. While the operation: of the gearbox was faultless, the gear ratios could have been spaced a little further apart. The engine has  a fairly broad power band and can pull wider gearing. And, while not a horsepower demon, it certainly has its share of beans, it felt as fast as an Elsinore, but it would be tough to say it was as fast as a Yamaha YZ.


One drawback of the higher revving engine is vibration. Not noticeable under racing-condition handlebar grip, it becomes apparent when you loosen your grip or when the bike is stationery and you wring the engine. This can be particularly annoying on the starting line, when the starter decides that he’s going to play games with the pack. By the time the moto gets underway, your hands will be tingling.

We mentioned that the power band is wide, but we did have one problem with the bike. It didn’t do it when it was real new, but as the break-in miles seated the rings, and blow by decreased, the engine began loading up if the throttle was whipped open while in the wrong gear for a particular situation. This was easily diagnosed as carbueretion problem. One that anyone can fix with a few jets, or a needle, and some spare time.

The KX250 is light. It has to be to be competitive in today’s weight conscious market. It won’t tire your body from having to heave it around. But what will tire quickly are your hands and arms. This is due to the suspension. For jumps and WFO whoopers and potholes the suspension is plush. In fact some of the smoothest landings ever were accomplished on the Kaw. But initially it is stiff, particularly on the little cobby junk that seems to infest the corners of nearly every motocross track. The front forks simply refuse to work. Everything that you hit is transferred through the forks and handlebars to your arms.

kx250_3We talked to a KX250 owner at a motocross, and he told us that the stiff ride wears away after awhile. In fact, he said that it was necessary for him to go to 20-wt. fork oil to keep the forks from bottoming on the real nasty tracks (like Saddleback on a Thursday). The marshmallow-like landings were still there, but horrendous bumps and ditches caused the units to bottom, once broken in.

The rear shocks were better in that they broke in right away (whether or not they will last is another question), but they produced some rump jarring when they were new, too. Which brings us to another point – the seat. The density of the foam used on the KX’s seat is too light. You sink right down to the seat base the minute you sit on the bike. There was also some reluctance on the part of the seat to spring back to its
original shape each time our rear ends lifted off as we rode. Whether this is clue to lack of “breathing”- in the seat, or whether this may also be attributed to the foam, it was uncomfortable nonetheless.

The Kaw corners well. Although we don’t particularly care for the Dunlop knobby fitted to the front wheel (it wears out quickly and has poor traction), the 4.60 tread on the rear wheel is a real traction getter. Front wheel washout was non-existent most of the time. Then, all of a sudden, it would give. You had to be quick to catch it. too. For the most part, the steering behaved itself and provided little trouble.

Stopping was easy too. The rear brake was a tad touchy, but to complain about it would be nitpicking. It is strong and controllable. The front unit was just as up to the job as the rear one. We experienced a bit of front-brake shudder when the bike was new, but it went away. Both brake hubs are aluminium alloy castings with magnesium backing plates. The front one is a full-width binder: the rear is half as wide. Both are cable·operated.

Levers on the chrome moly handlebars are the typical breako specials that plague Japanese machinery. They do, however, sport grit covers that are a nice touch. The plastic quick-turn throttle is fitted with some harder than Dohery but better than Yamaha enduro grips, which most people will like well enough to leave alone.

Foorpegs are of the folding variety, but are not spring loaded. It’s a shame, too. as they sorely need to be. Early pegs broke off because the chrome moly used was of too thin a wall thickness; but we understand this has been corrercted at the factory.

The fenders are flexo-flyers, but crack easily and will require immediate replacement.

With DID rims and a smartly-styled green fuel tank, the KX brought out the curiosity in people wherever we took it. And when it fired right up with a minimum of hassle, well, they were even more surprised. lt is an easy machine to ride and on which to compete. lt does nothing radically; but does everything well. The KX owner is going to have to change the oil in the front suspension and then wait for the units to break in, re-pad the seat. get some sprong-loaded footpegs and probably change the front tire. But he needn’t do so to be competitive.

This year Kawasaki is slipping their ace, the KX250, into a deck that is already loaded with aces – CRs, VRs, YZs, CZs and now the KX for MX. It`s your- hand to play out. Go ahead, you can`t lose.

4 Responses to “1974 KX250 Cycle World Test”

  • fivestar:

    fivestar…

    fivestar…

  • I follow your blog for quite a long time and should tell that your articles always prove to be of a high value and quality for readers.

  • yah:

    I own the last evolution of this KX….bought it new in ’76, and am STILL amazed with the brute acceration of this old piston-port.
    The only real diff from this and the ’76 is the paint scheme (76 was metallic green with black fenders..)
    NO CR,NO YZ,NO RM in that era could see anything but the faint Kawaski on the rear of the seat as that monster Dunlop spewed roost!!!!…
    and it still does with a few parts gone by….the tank requires a filter, and the original DeCarbons were replaced with Fox Gas in the 80′s, and were it not for the limitations of Kawasaki to keep all originals still available..
    I still ride it, and i’ll NEVER sell it….

  • George:

    Yes I bought a 1976 KX250 brand new and it flew. There were times the 500′s started in front of us 250′s at Carlsbad and I would catch up with some of the slower 500′s. When we both exited a turn at the bottom of a hill I could pull along side that 500 and keep up with him! I don’t remember the handling being that great and a friend of mine and I moved the lower shock mount further forward for more travel. I don’t remember the suspension being that great either, but it was a bitchen bike! I wish I could have put that motor in my 1980 Suzuki RM!

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