As we jump in the vault for this week’s Church feature, we travel back to 1997, a time of change and consternation amongst off-road enthusiasts. Why? Because this was the year California really cracked down on two-stroke off-road motorcycles. A look at showroom floors today reveals (thankfully) that two-strokes haven’t exactly died off, but are far from prominent. Instead, the four-stroke era kicked in, and here we have a test of some modest trail bikes – the 1997 Honda XR400R and Kawasaki KLX300R. Far from speed demons, both bikes are fun on the trials. How fun? Let Len Nelson tell you…
Jun. 25, 1997
Photography by Staff
We’re willing to bet that most off-road enthusiasts are acutely aware of this by now, but in case you haven’t heard, two-stroke off-road vehicles manufactured after January 1, 1997 are now prohibited from operation on public lands in California. For those of you operating two-stroke machinery outside of the Golden State take note, for this may very well foreshadow the future of off-road vehicle design. Sure, consumer demand still influences direction of the motorsport market, but laws have a funny way of creating rapid change. No need to remember the Alamo, just think back to when three-wheelers were on showroom floors. It’s a raw deal for many reasons but let’s face it – are you really going to wait for clean-burning two-stroke machines to go into mass production? Give us a call when they’re ready – we’ll be out enjoying the latest thumpers until then.
A while back we were invited by Kawasaki to their KLX300R introduction in Idaho. We were so completely delighted by the bike’s handling prowess that we hurried to compare it side by side with one of our all-time favorite four-stroke trail bikes – Honda’s XR400R. The XR is powerful, nimble, and way too much fun. Both bikes present great values, but which one is right for you and why?
Apples to Oranges We admit that comparing a single cylinder motorcycle to another that has nearly 100cc of additional displacement may initially seem unfair. However, we found that given the proper conditions the KLX could hang with the Honda. Sure, we initially considered throwing the XR250R in the ring, but after spending considerable saddle time on the smaller Honda and the Kawasaki, it’s clear that a fair fight would have to include the 400.
Let’s get the displacement issue out of the way. Using the highly accurate MO Dynojet dynamometer to measure rear wheel torque and horsepower, we’ve generated plots to illustrate the unique power characteristics of each bike:
As one would expect the KLX, being based on the KLX 250 model, lags behind in both peak horsepower and torque. Clearly the XR has muscle to flex, but it also has more weight to carry. In order to level the playing field and better understand the relationship of power to weight, we’ve calculated the power-to-weight ratios for each bike. For simplicity’s sake we’ve used each model’s dry weight. Since the KLX is fairly lean, it was not without surprise that both bikes exhibit similar power-to-weight ratios. The XR snarls down the trail with a ratio of .107 horsepower per pound while the KLX is right on its tail with .106 hp/lb. As you can see, a rider’s ability to extract maximum performance and use it to his advantage with either machine weighs more here than any relative lack of displacement.
Despite similar power-to-weight ratios there are other design issues that vastly affect the personality of each machine’s power delivery. If you’re an aficionado of high revving motors, then you’ll prefer the KLX’s free-revving spirit over the grunty XR. In stock form the KLX will spin approximately 750 rpm higher than the XR, producing power longer. Its combination of dual overhead cams, considerably less reciprocating weight and Kawasaki’s Electrofusion cylinder bore makes these higher engine speeds possible. Unlike the XR, the KLX is water-cooled, leading one to believe it should retain peak power longer as well.
Although the Kawasaki delivers good power, most aggressive riders will be searching for a little more. This initial desire for more power however, may actually be a desire for increased responsiveness. Kawasaki’s engineers decided to fit a CV carb to the KLX. Constant velocity carburetors are common in street bike applications where they produce smooth acceleration and reduce engine bog. CV’s prevent an engine from being fed more fuel than it can handle.
With a CV carburetor the speed at which its slide opens is dependent more on engine vacuum than physical throttle response or position. Whack the throttle open or roll it on quickly and the slide will open only as fast as engine vacuum builds. Therein lies a pitfall with our CV-equipped KLX — it turns what is normally a fairly aggressive animal in all other areas into a docile mule. Out on the trail these drawbacks are obvious. If you need a burst of power to blip over an obstacle or steer through a wash, you had better anticipate what you want from the motor well in advance. Be prepared to take a stab at the clutch too. Throttle response just isn’t there.
If you like low-end grunt, you’ll love Honda’s XR. It rapidly builds torque off idle until about 3000 rpm. The engine prefers to be short-shifted to take advantage of its narrow range of torque. We did experience some hesitation and stumbling when the throttle was banged open, a common complaint with XR’s. Despite this minor carburation snafu the XR will out-torque, out-accelerate and outrun the KLX in a straight line. Guess that old adage — there’s no replacement for displacement — still holds true in some cases. Based on power output in stock form though, we prefer the smoother, more widely-spaced power delivery of the KLX for beginning to intermediate riders. Of course those who know how to work a torquey four-stroke for all its worth would prefer the XR every time.
Depending on where you ride, sound might not be an issue. Since both bikes are equipped with removable baffles you have the option to running with them in or out. Removing baffles increases power levels and does not affect the spark arresting capabilities of either machine. Running with baffles installed might be a good idea if you are a new pilot and would like to limit power output, or have concerns over sound levels where you ride.
Last year we reviewed Honda’s 1996 XR400 and experienced troubles with its five-speed gearbox. It refused to up-shift when the engine became very hot. This problem first occurred at a motocross track on a hot day, and became frequent enough to raise eyebrows. It seems our difficulty was an isolated case. Despite our direct prodding of American Honda, along with XR owners we encountered on the trail and inquiries to Honda dealers, we were unable to rustle up a similar report. Honda claims the ’97 XR’s gearbox is identical to last year’s (the only noteworthy difference is the addition of stronger clutch springs and a redesigned lifter), and our newer unit performed without a cough. We found shifting to be smooth and precise. Our clutch felt strong and never evidenced any slippage, with clutch lever pull acceptably light for a 400.
Not so the KLX300. Kawasaki’s previous model KLX 250 was plagued with shifting woes of all sorts. Reports of false neutrals, missed shifts and a tendency to pop out of gear were not uncommon fare for KLX owners. Kawasaki claims these areas have been massaged on the new 300R model, but we managed to turn up a small bug. When we initially tested and wrote our first impression of the KLX we mentioned its six-speed transmission jumped out of gear on a few occasions. This always happened while under load and hard acceleration. Having now logged many more miles on the green machine, this fault has become more prominent and deserves additional attention. On the up side, clutch pull is joyously light, notably lighter than the XR, and the clutch itself held up well under abuse.
Gear ratios for both bikes are well spaced and should suit most riders. The KLX could benefit from taller gearing, as it quickly topped-out along wide-open stretches so typical of California. With its stock final drive configuration, the KLX’s first gear is best reserved for pulling stumps – we’d suggest losing two teeth off the rear sprocket.
Both machines are fitted with modern, adjustable off-road suspension systems that will suit you just fine for trail riding. Race either of these bikes though, and you’ll have to go for a damping revalve job along with springs at both ends. Dialed in for aggressive riding, our XR seemed overly harsh. Its front end was prone to deflection, and the rear kicked when the shock got hot. Headshake occurred at speed no matter what we did. The KLX suspension on the other hand is very plush by comparison, but if pushed hard will bottom and hop. The shock also seemed to overheat quickly too. Any good suspension tuner can right these wrongs, although our consensus is that the KLX equipment offers a better starting platform, requiring less work and money to make it race worthy. Our test bikes both came equipped with identical Dunlop tires – K490 in front and K695 holding up the rear. These tires offer a nice combination of wear and traction.
In stock form we feel the KLX’s handling is superior to that of the XR’s. It turns better, tracks more securely at speed, and soaks up most anything it encounters with little upset. It does this all while retaining an incredibly plush feel. Much of the KLX’s sure-footed handling can be attributed to it’s rigid perimeter frame, overall geometry and 43mm upside-down cartridge forks which are supple yet responsive. Again, if you’re just going to trail ride either bike you’ll love them both in stock form. Overall though, the KLX wins our vote in the handling department.
Honda’s price tag on the ’97 XR is a bit higher than Kawasaki’s KLX, so we expected more from the Honda — more than 100cc of additional power. With the Honda you’re getting a bike that has been carefully cultivated and is a good race-ready mount.
The KLX300, although a great package and a terrific platform to build on, is a machine that, in our opinion, still needs some refining. Choosing between these bikes depends on your bottom line. You must ask yourself what is important to you, and for what purpose the bike is intended. If you want a playbike and have limited riding experience, the KLX is a no-brainer. If you are a larger or more aggressive rider you’ll most likely be happier with the XR400. We chose the XR as our favorite mount because it is a more refined package and a good overall value. We decided to keep the KLX for a long-term evaluation though, so don’t fret you die-hard Team Greeners — you haven’t heard the last from Kawasaki’s newest four-stroker yet!
Model: 1997 XR400R
Engine: Air-cooled, SOHC four-valve single
Bore x stroke: 85 x 70mm
Carburetor: 36mm piston-valve
Wheelbase: 56.1 in.
Seat height: 36.6 in.
Fuel capacity: 2.5 gal.
Claimed dry weight: 257 lbs.
Model: 1997 KLX300R
Engine: Liquid-cooled, DOHC four-valve single
Bore and Stroke: 78 by 61.2mm
Carburetor: Keihin CVK34
Wheelbase: 56.5 in.
Seat Height: 36.4 in.
Fuel Capacity: 2.1 gal.
Claimed Dry Weight: 231.5 lbs.