Suzuki Stinger 125cc Road Test
Motorcycle Illustrated March 1971
To Suzuki's credit, never before has one of their motorcycles given anything more than the kind of trouble that is redeemable at the turn of a screwdriver. From the reports of other Stingers, this one was one of those unfathomable production drop-outs, whose salvation only ever lies in a transplant of everything save its skeleton. To read this test as representative therefore of Stingers as a whole would be unfair, but read on anyway.
When I collected it, the air cleaner had been removed in an attempt to make up for over-rich carburetor settings. Smaller jets were unobtainable for the Japanese set instruments, which had proved themselves to be unsuitably jetted for our climate, at least on this particular model.
The Stinger was duly returned for correction and collected some days later, apparently serviced and running properly. New carburetors, an air cleaner, re-timed ignition, and a new set of correct grade sparking plugs suggested that this time things would be different. Up to a point they were. Performance had picked up noticeably all round. Tick-over was steady at 1300 rpm, acceleration had improved and so had the rev ceilings, but not by a great enough margin to satisfy either Alan Aspel or me that optimum efficiency had been achieved.
Suzuki state that maximum power is produced at 8500 rpm. In my experience with other Suzuki machines, this is perhaps the only weak spot in the Suzuki company's claims. In most cases, their machines tramp on past the maximum claimed power revs, and only really get into their stride once into the red painted danger zone on the rev counter's face. Believe me, it has caused some headaches in the past when attempting to nail down gear ratios, speed and revs. Once accepted however, the problem becomes little more than a characteristic to remember.
Then along comes the Stinger and shatters the tradition by either producing less power at lower revs than the manufacturers claim — which I doubt — or is at fault — which I suspect.
Although Suzuki claim a maximum power development of 15.1 bhp at 8500 rpm, on numerous occasions, the Stinger's engine would not even reach 8000 rpm in bottom gear, let alone any of the higher ones. And, when I pulled in to a lay-by in a frustrated attempt to discover the cause of the power loss, it refused to reach more than that in neutral, free of load, under full throttle. 7000 rpm in any of the higher gears was the limit at such times, and 7000 is supposed to be the maximum torque development speed. In the face of the slightest hill or headwind, road speed would drop so low as to require fourth or even third gear at such times.
As time progressed, the engine performance became symptomatic of (once more) an over-rich mixture, especially on the right-hand side cylinder, which had caked up its spark plug with a soft brown ash.
Another suggestion of poor carburation was the ease with which the engine would start from cold without use of the choke lever. On frosty mornings it was necessary, but not otherwise.
So much for the worst. What about the brighter side? Happily, it was blazing bright, and it was this that, despite the previously mentioned engine performance troubles, ensured a balanced outlook on the Stinger. For, whereas the engine misbehaved itself, at times showing its true self and at others refusing to perform, the general behaviour of the rest of the machine was faultless.
Handling of the Stinger was so good that, as Roy Buchanan said, it was dangerous. Of course, such a claim is an exaggeration of the facts, but I know what he meant. To change line required nothing more than a thought and the Stinger responded instantly and exactly. Small section tires, low weight, light steering, and a responsive engine combined to return an agility as yet not experienced on any motorcycle, whether roadster or racer. Perhaps the exception to that was the AS50 (50cc two-stroke sporting single) Suzuki.
Although fine on long sweeping curves, the razor-sharp ability to corner quickly did not show up, until a succession of tight yet contrasting bends on a minor road were attempted, and then did the Stinger go! The back end was slightly under damped, but without any apparent effect towards road holding.
Under damping seems to be common on small motorcycles, so presumably the difficulty in arriving at a compromise, acceptable for all riders and passengers must favor softness. For instance, two-up, even with the adjustable rear units " on maximum strength, spring strength was too soft. But with Alan solo, undeniably too hard, yet in each case, without any appreciable deterioration in handling. The conclusion being, therefore, that Suzuki have to their credit designed a frame capable of withstanding the awful motion of soft springing without noticeable distortion.
Late one fine afternoon, with a cold sun low over the gentle hills of the Essex countryside, and black elms like great networks of veins silhouetted against the pale sky, I hung the 'bike on its throttle cable and, suspended on that tensioned wire, we swung along the narrow, twisting lanes going nowhere but onwards.
Somewhere along the route, a police-driven Cortina GT pulled out in front of me and accelerated away along the short straight road. I caught up at the first bend, and" held my place close behind. The passenger in the car looked around and studied me for a few moments, then turned back to his driver. They talked. Trouble, I thought. He looked around again, and the car accelerated to the next bend where, instead of slowing, it scratched around in a tight drift. I followed. Our speed was somewhere between 50 and 60 mph. The passenger grinned, just a little, but a grin all the same. For maybe four miles the police driver skilled his car around one bend after another, but the Stinger held on. Not by reason of its speed, but by reason of its road holding ability. I think it surprised my friends of the moment. It certainly impressed me.
Grounding was difficult. Once or twice, right on the limit of adhesion, my feet tippy-toed lightly, but unless a pillion passenger was aboard, scraping any part of the machine was bordering on the impossible.
Alan discovered, to his delight, that cornering fast on a certain series of poorly surfaced curves in Surrey induced the rear wheel to hop as it passed over the bumps. This might not sound good, but remembering my earlier argument over the difficulties of lightweight machine suspension spring strength, I would suggest that the mere fact that Alan was able to enjoy, and obviously therefore control movement is suggestive of rare handling quality. At no time did the front end do anything but point in the direction it was intended to, and never was there any suspicion of unwarranted movement at the steering head. Neither the frame nor the swinging arm became involved in any flexing problems, so that at all times the ride was completely assured and predictable.
Braking was reasonably good, but the little sis devices, particularly the front, were not really up to the job of stopping quite as adequately as the speed of the machine suggested they should. Two-up riding brought home their weakness. They, as with most of the cycle parts, are identical to those used on the Trailcat and from my point of view, trail bike brakes cannot cater for the requirements of fast roadsters.
I have said it before, and shall say it again. Japanese bulbs are rotten. For why else should an otherwise identical range of motorcycles display such a variance of lighting characteristics as to suggest that they come from different factories? The Trailcat lights were magnificent things which far exceeded the requirements of the 'bike, whereas those on the Stinger were mediocre. Dip beam was fine, but main beam was nothing but a vague scatter of light without the vital degrees of lift so necessary beyond dip. Another bulb would undoubtedly cure the trouble.
Thoroughly appreciated were the flashing indicators, particularly for overtaking and night riding, but the activating switch spoiled the set-up. Situated on an alloy block next to the throttle, its horizontal movement ensured that instinctive operation was out of the question. In a pair of riding gloves, Winter ones at that, locating any switch is difficult enough. If, however, the switch is a vertically operated unit, it requires only a sharp flick up or down, as the case may be, to operate it without the need for location; thumb movement ensures success. Incorporate two other controls to be operated simultaneously with the switch, and operation becomes tricky. Then ensure that the hand operating those controls has to be re-located to activate the awkwardly placed switch and efficiency is halved. Finally, design the switch so that it requires an uncomfortable and unnatural thumb movement to use it and all pretence at efficiency is lost completely. And yet that is exactly what Suzuki have done.
Flashers are required precisely at the same time as is the front brake (direction changing requires a change in road speed) and the throttle (the same applies). In my opinion, the dip switch and flasher switch should both be mounted on the left-hand handlebar, and both should move in line with that of the machine.
The ignition and lighting switch was thoughtlessly mounted under the left-hand side of the fuel tank nose. Headlamp flashing is a very necessary signal on many occasions on the road, but on the Stinger was, for all practical purposes, impossible.
Silencing of both exhaust and induction was good. Only in the medium rev ranges under hard acceleration were any perceptible overtones of irritating noise evident and that, I suspect, was mainly induction roar and therefore limited to the rider only.
The concept of a machine such as this one owes much to America. As testing proceeded it became pretty obvious that it was not designed with any pretentions to serious motorcycling. Although the riding position is comfortable, it is at loggerheads with the other qualities of the machine. Handlebar, footrest, and seating relationship is pure town or low speed touring, without any concessions towards sportiness or wind cheating which, frankly, the Stinger could do with.
Only two motorcycles have ever come my way that have ever suggested to me, by merit of their performance style, that they needed clip-on handlebars, rear set foot-rests, and back-stop seat. One was the Kawasaki Mach III, and the other was the Stinger. In its present trim any pretentions to a wind cheating crouch are nominal, no more. Yet even so, such an action had a definite effect upon performance, especially when riding into the wind when, at the machine's optimum speed, another five mph could be persuaded from the engine. Given the full English treatment, including a small racing fairing, the useable top speed of the Stinger would be raised by as much as ten mph.
Alan squeezed more from the 125 twin than I did, which only rivets home the need for a small frontal area, Alan weighing some 42 lbs less than I do. He, on a couple of occasions, forced the speedometer
needle around to 80 mph, which even allowing for the five mph speedometer exaggeration is an extremely creditable speed for such a tiny engine. Moreover, it agrees with the manufacturer's claimed top speed. I could not manage more than 69 mph, and found that fourth gear gave me as good a turn of speed as fifth.
Petrol consumption suffered from the engine peculiarities. At top speed cruising, only 41 mpg was accomplished, while more sensible, all-round commuting, shopping and testing speeds returned 57 mpg. Both could be improved on by a correctly tuned engine. Oil consumption was something better than 300 mph, although due to a faulty oil injection gun at a filling station, I cannot state exactly what.
Starting was good. Usually the engine burst into life on the third kick, a characteristic of diaphragm operated fuel taps, even with a free flow device as fitted to the Stinger.
Fashionably dressed in the trendy colors of the season — lime green tank and matt black exhausts — Suzuki has produced one of the best looking machines of the year, and this is probably the greatest appeal of the 'bike. To most people, non-motorcyclists as well, it was all too apparently irresistible. Few will buy it because of its sensible specification. Sales success will be directly attributed to appearance.