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Period Roadtests

Kawasaki 350 BigHorn

Kawasaki's 350 Bighorn single is the first big bore enduro machine from Japan

Project name
Back in 1964 one of the Spanish motorcycle manufacturers released a new type of machine to the American market. It was the first production light- weight street/trail machine. It caused the motorcyclists, and even great num bers of non bike enthusiasts, to really take a second look at this new machine. It was a single cylinder two stroke with semi-knobby tires, and was also equipped with full electrics to make it street legal. A few motorcycle maga zines immediately had this new honest to gosh street/trail machine on their covers. There was a lot of excitement over this new breed.

Most thought it was a keen idea, but what exactly could it be used for. In those days a motorcycle rider either rode on the road or in the dirt. There couldn't possibly be a machine that could do both well or could there?

A few years passed and in the mean- time the industrious Japanese factories were producing a multitude of small displacement woods type trail ma- chines. They had knobby tires, lights. and usually a monocoque stamped steel frame. Most of them were in the 90cc bracket and the power was limited. They were heavy for their size, but they would take you just about anywhere.

Then in 1967 one of the Oriental factories released the first real mass production street/trail (or enduro) type machine. It caught on like wildfire, the time was ripe. It was light in weight. attractive, street legal and was at home on the trail or road. Since then the Japanese and European factories have been hard at work producing newer and better enduro type machinery. The Japanese machines had the advantage of being available in large quantities, with high quality components and good electrics. The European machines were a little more expensive, but they had the upper hand in the handling and suspen- sion departments.

It was only inevitable that one factory would soon come out with the best features of both. A roadster and a dirt bike. Kawasaki's release of their 350cc two stroke single probably surprised some of the other manufacturers who have been contemplating the same move. In our testing of the Bighorn we were rather surprised with some of the new ideas that Kawasaki has in corporated in the machine.

In an attempt to incorporate all the good qualities of an off road machine, some of the frill and dash used on other bikes of this type are missing. The main color scheme is brown with white back ground on the gas tank and underside of the fenders.

In the comfort area, the Kawasaki factory has gone all out to top the other enduro machines. Excepting the handle bars, the Bighorn is exceptionally com fortable. The saddle is wide, long and thick and provides optimum cushion for the smallest or largest of riders. The position of the footpegs have also been well thought out. They're placed low and back as compared to most other Oriental machines of this type. The re sult is comfort as well as good balance and weight distribution when standing on the pegs. Another step in the right direction.

The handlebars are one item we didn't care for at all. They wanted to pull the rider forward excessively in a crouched position. OK for moto cross, but a hindrance for an enduro mount. Replacing these with bars having more of a rearward sweep would arrest this situation.

In our off road testing of the Bighorn we ran into a couple of areas of dis comfort with the engine and transmis sion of our test machine. The potential output of the 33 horses was there, but we just couldn't get them to respond properly to the throttle control. The per formance was generally smooth at all speeds, but the power response was either slow (or sometimes non-existent) when we needed that extra surge of power. We discovered that the spark plug was excessively oil coated. Replac ing this with a new plug helped, though the engine still did not respond as it should. There apparently is a little fine tuning, mainly in the carburetion sys tem, that should cure this situation. We rode a couple of other F5 machines that had been properly tuned that didn't have this poor throttle response problem. Therefore, it is not a serious thing, just one of these tuning situations.

The transmission and clutch assembly are large beefy units throughout. They were built to last under just about any type of treatment. The clutch functioned perfectly and was absent of any fading or grabbing problem. In the area of the transmission we again had some of those adjustment problems. We found that we had to be rather careful in engaging gears, especially when the en gine was put under a load. Invariably whenever we were pulling up a hill or trying to accelerate out of a situation, upshifting or downshifting resulted in finding a false neutral. This meant stop ping and starting over again. Most irri tating. Again some other F5s that we rode didn't seem to suffer this problem.

Another thing that is bothersome is trying to locate neutral when the ma chine is stopped with the engine run ning. It's all but impossible. This too seems to be inherent with most Oriental machines. Starting the engine was usually a one or two kick proposition. No complaints here. The kick arm is a long, quite long, item. This provides more leverage for kicking through those addi tional inches in the engine. Here we also found an area that could use improve- ment. We quickly found that the pivot design of the kick arm has very close tolerances and would jam up when sub jected to mud or dirt. Increasing the clearances in the pivot area would alleviate this.

The engine of the Bighorn, including the induction and exhaust system, is noisier than most of the 250cc ma chines. This is only to be expected with the additional inches and power in crease. But it really can't be termed as objectionable. Kawasaki has in corporated a couple of the features on the Bighorn that they use on most of their other bikes. The oil injection sys tem is standard as well as the now popular GDI (Capacitor Discharge Igni tion) and the surface gap plug. One thing that is really nice about the CDI system that you mud riders will like, or anyone for that matter, is that the igni tion is virtually waterproof. No points to adjust, no timing to reset.

The wheels of the Bighorn are also something new for an Oriental produc tion machine. The rims are the alloy type as used on many of the European ma chines. On top of being stronger than steel rims, they reduce some of that unwanted weight. The tires are the very popular trials universal types with a 4.00 x 18 rear and a 3.00 x 21 front. The lighting is typical of most of the Japanese machines, excellent.

The main calling card of the Bighorn is its fine handling characteristics. This Is the one area that the Oriental dirt machines have been surpassed in by the European bikes. Apparently a lot of test ing and research has been going on back at the factory in the suspension and frame geometry departments. The rear shocks are a departure from most other Japanese items in that the damp ing and spring tension have been well matched. Most importantly the damping action of the shocks works very well. We never had the units top or bottom. and the good damping action kept the back end from jumping around (or trying to swap ends) in the rough stuff. Up front, the forks are a departure from conventional suspension units. These new Hatta forks will probably become a pattern for future off road machines to follow. The spring tension rate and damping action have been ideally matched. They not only provide a very comfortable ride, but they function per fectly. There never was a situation or obstacle that could cause them to top or bottom. This combined with the rear units keeps the machine going straight where other machines might start walk ing around.

A closer look at the forks shows that the designer was thinking of more than just good actuating units. The bottom legs have not just one, but two positions for the axle. By placing the axle in the auxiliary position the wheel base can be shortened or lengthened about two inches total (one inch in either direc tion). This is accomplished by turning the lower legs 180° so the auxiliary axle position is either forward or rearward of the standard axle slot. This gives a total of three positions for the axle, and there fore an option of three wheelbase figures.

The upper and lower triple clamps are designed to permit even more adjust ment. Both triple clamps have straight through holes (rather than a tapered or stepped one at the top), thus permitting the fork tubes to be raised or lowered. This permits even further adjustment of the geometry. There was one reaction that was a bit disturbing about the front forks. In sand or rough ground the fork tubes did have a tendency to wobble as if they were loose. This not being the case, we discovered that the tubes were flexing considerably when the wheel was under side stress. A fork brace would probably remedy this. but even better the fork tubes could be made of a harder, thicker or higher quality steel.

The other half of the handling im provement is in the design (or geometry) of the frame. The whole frame sits lower to the ground than other Oriental enduro machines. The engine and foot pegs are further to the rear and the rake and trail of the front end are evenly matched to cross country riding conditions. Most other Japanese enduro machines have quite high ground clearance dimensions (a la trials machines). This results in such a high center of gravity that han Iling can become tricky and even unse cure above the 35 mph mark when riding in the rough. Not so with the Bighorn. It is extremely predictable at low or high speeds in just about any kind of terrain. Popular belief is that lower ground clearance and center of gravity poses a problem in going over logs or rocks. Not so. The European machines are proof of this. In the engine department. Kawasaki

has stuck to its popular rotary valve two stroke design. The dependability and potential of these engines has long since been proven. The rating of this engine in stock trim is 33 horsepower at 6.500 rpm and 28 foot pounds torque at 5,500, both of which are probably about right. The actual displacement of the engine is 346cc, which will allow it to be placed in both the 350 and 360 classification. The unit construction power plant also encloses the wet multi plate clutch and five speed transmission.

Kawasaki has taken the first step into the big bore enduro market on a high production basis. The demand is here for these machines, and to go a step further Kawasaki is the first of the Oriental manufacturers that has taken a giant step forward in the handling department of these street/dirt machines. They have come up with a machine that compares favorably with the European mounts. There were a few areas of adjustment that properly serviced would bring the performance up to par. If you're the type that wants those addi tional horses for serious (or not so serious) trail or enduro riding, the Big horn should well fill the bill.

Type single cylinder, rotary valve two stroke
Bore and stroke: 3.17x2.68 in. (80.5x68.0 mm)
Displacement: 346cc
Compression Ratio: 6.8:1
Max. Horsepower: 33 at 6.500 rpm
Max. Torque: 28 ft. Ibs at 5,500 rpm
Ignition: transistorized capacitor discharge
Lubrication: oil injection

Length: 82.0 in.
Wheelbase: 55.0 in.
Ground Clearance: 9.0 in.
Dry weight: 268 Ibs.

Front tire size: 3.00x21
Front brake type: internal expanding
Rear tire size: 4.00x18
Rear brake type: internal expanding

Type 5 speed constant mesh
Clutch: wet, multi plate
Countershaft sprocket: 14T
Rear wheel sprocket: 45T

Indicated highest one-way speed: 88 mph
1/4 mile terminal speed: 75 mph
1/4 mile elapsed time: 16.5 sec.

Air Filtration: washable foam
Battery type: 6V-2AH

Fuel Tank: 3.0 Gal
Fuel Reserve: 5 Gal
Oil Tank: 1.7 Qts
Gear box: 1.25 Qts

Front suspension: telescopic, double dampening
Rear suspension: adjustable shocks
Frame type: tubular, double loop

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Period Roadtests

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