When I passed my test I rode the 200 around to the nearest dealers, and there in the corner was a two year old Yam YRSF 350 - with rubber rings in the clock. And I bought it. It really was in the corner, as well. It was in excellent nick but had 10000 miles on the (rubber topped) clock, a figure in those days that was considered dangerously high for a two-stroke.
Back then, it was a time of great Brit versus Jap acrimony, the most audacious feat available to a madly wheelie-ing YDS7 was to out accelerate a Triumph Bonneville. The greatest opposition to these bikes came not from other motorcycles, but the wilfully tortoise like British bike owners who persisted in the opinion that the Jap crap wouldn’t last five minutes anyway. There was always the evergreen Thrunge Wangler owner who, hands deep in pockets, would wave a foot vaguely in the direction of the engine, assuring you that he could hear that the big-ends were about to explode even if you couldn’t.
My first impression of the YRS was of a taut, buzzy machine with a surprisingly deep engine note which was dominated in the lower rev range by a considerable intake roar and ringing cooling fins, all of which resonated loudly through the petrol tank. In a sense, the bike appeared to represent access to pure power, and this seemed at odds with its apparently user-friendly but not over-sophisticated fixtures and controls.
At high revs it never quite produced the power attributed to these machines - too much wailing under load at sustained high speeds (and that was only me), although plenty of raa-ger-jjjjjj [Eh? - 2022 Ed.] when dropping through the gears. I was surprised to discover that the 350 had a power band even narrower than the Kawasaki H1 500 triple, and, indeed, the same seems to be true for later RD400s. The H1F I now own is both faster and more tractable. The main feature of the YR5’s power band was unpleasant jerking followed abruptly by endless and often unwanted wheelies.
It had for the day a remarkable rate of acceleration, usable at up to 10000rpm, and which always had your bum sliding back down the seat and, more often than not, had your feet scrabbling about trying to find the footrests. It also had a light front end, not helped by high bars - I’ve had the whole plot lifting when changing rapidly at high revs from fourth to fifth (top). Thus, endless changes were needed to keep the bike moving. Where something as gutless as a Honda 400 four could trundle along in one gear, the Yam had be screeched thru the box to keep up. This necessary (tee-hee) style of riding meant the chain lasted only 8000 miles and the plugs needed replacing every 2000 miles. Try riding very slowly and the plugs would oil up. Fuel could be as low as 28mpg, although long rides could return as much as 45mpg.
Friends who owned four strokes looked with contempt upon the consumable destroying nature of the power delivery and the insane mechanical clatter, but the speed of the YR soon made them eat their words and I was able to run the bike for 15000 miles with no major mishaps. The only maintenance needed were quite frequent decokes, plug changes and a new set of points. After 8000 miles it produced the most awful clonking sound. I eventually lifted the barrels and sort of pulled things about in the manner described by the manual, and as nothing appeared glaringly amiss, I threw it back together and it ran trouble free for the next 7000 miles.
I was always conscious of the vagaries of two stroke behaviour. It would produce the most awful clonkings and scrapings, usually on a long run after it’d become hot. I remember in Snowdonia on a cold and rainy Sunday afternoon, accompanied by an equally noisy and increasingly more irritable girlfriend, the engine suddenly exhibiting those horrifying clanks and rattles that precede both big and small end demise. It was a nightmare, and there were many times when I vowed to get rid of the bike and buy a four stroke, but it never actually broke down or blew up. A mechanic at a local dealer told me that in five years they'd only one Yam in for a bottom end rebuild, and estimated that 20000 miles was reasonable between rebuilds.
An enduring problem, however, was the silencers which clogged with oily goo and two stroke throw out. Constant wire brushing of the baffles helped. Coked up silencers caused the engine to surge under heavy acceleration. Tons of yucky blue smoke, dog ends, fish bones, etcetera, would pour out onto the windscreens of disgusted motorists. Ridden at a leisurely pace for more than a couple of miles left the bike needing 4 good thrashing to clear out the system and make it run cleanly again. Although this could be a major problem, the reliability of the bike over 15000 miles of sustained thrashing somewhat compensated. The gearbox was superb and spoiled me for later bikes - it could be flicked so fast between gears with no fear of a missed change that I could often take bikes the YR had no right to beat.
The handling helped as well, far from perfect (it would twitch and then break away the back wheel on long corners) the frame was stronger than many of its contemporaries and the geometry and light weight were especially useful in tight corners. A scraping footrest indicated not your limits but how much you had left until it folded up completely. With a passenger you could ground the silencer as well. The forks bottomed out frequently (not helped by all the wheelies) and could become frightening with a passenger on board. The front end could be kept on the tarmac if gear changes were made before entering the power band, but even then the forks could top out jarringly - the rider managed to remain more or less in control.
The TLS front drum provided a degree of sensitivity that could get you out of trouble when the going got rough, but the brake could fade under frequent abuse. The rear drum liked to lock the back wheel. Brake shoes lasted eight and twelve thou on front and rear. When I nipped inside a Tiger 650 I knew there was nothing much wrong with the handling or braking. Top speed varies depending on what magazine you read or to whom you talk. The police were kind enough to give me a radar trap reading of 86mph.
I once raced a Reliant Supervan (yikes) down a steep gradient, which claimed 90mph (it was packed full of cackling bikers) and it took me ages to get past. Yamaha claimed 105mph, but 95 to 100mph seems more realistic. It wouldn’t pull top gear two up or into a head wind, unless you first raced her through the gears, which is not an acceptable excuse for speeding...
Like many young chaps, I used to get into a lot of races. Usual thing - stop light Grands Prix to epic battles. Once, carrying a 13 stone passenger, an optimistic Honda CB250 owner raced us all the way from Snowdonia to Birkenhead. At every stop he would catch up and then try to out accelerate the Yam (and fail). This was all acceptably good fun until the last five miles after we’d had the temerity to catch him up after our second fuel stop. Outraged, he produced a do or die, head on the tank effort to beat us, oblivious of the fact that we were now speeding through a built up area; urged screamingly on by my desperate to win passenger who was using an imaginary whip on the rear wheel (why are some pillion riders never scared?)
I indulged in a fit of motorcycling madness, the exact details of which I'll leave out other than to tell you that it was the nearest I ever came in the post-potty period to suffering an uncontrolled bowel movement. Er, victory was mine, but at the cost of an engine, subjected to 130 miles of full, throttle abuse, that sounded like it was about to explode - I feared that permanent and costly damage had been wreaked upon it - and to our ear drums. The volume was deafening. Both bike and I spent a couple of hours cooling down, after which I gingerly prodded the kickstart - every rattle and clonk seemed magnified even to my dulled senses, but it continued to run perfectly. My passenger was so impressed that he bought a RD350 instead of a XS650.
Once, a Kawasaki H1B 500 passed in the opposite direction. I turned around to have a good look at this rare example of a machine I foolishly adored. The Kawa was two-up and the pace was moderate until at a road junction a Bonnie owner plonked his wheel over the white line like he meant business. We each put our bikes into gear, edging forward, the Kawa pillion holding tightly onto the grab rail, waiting for ages for the light to change from red,
The light turned amber, the Bonnie lunged forward. I slipped the clutch, engine in the red zone, the rear tyre Squealing, front wheel up in the air until I banged her into second gear. The Bonnie was dropping back, I hit 9500rpm in second and changed up. I was aware of the Kawa behind me, losing a little speed as he changed gear. The speed with which I could change gear kept me ahead. I snatched a quick glance over my shoulder as I flicked into fourth, the Kawa was ten yards behind and the Triumph the same again. I wound up the revs in fourth, discovering new limits to the Yam’s performance as it continued to pull to 10000rpm at a registered 94mph.
I recall as I flicked into fifth, slightly amazed at what the bike was doing, how my eyes rapidly scanned the road ahead (with too many parked cars and cars trying to park). Distant targets rushed at me at a fearsome rate, every movement sent shock waves to my heart, every car nosing out of a side-turning a nightmare collision about to happen. The Yamaha screamed deafeningly, with 98mph on the clock, the front end skimming left and right - both bike and I had reached their usable limits.
The next set of lights were on red and closing rapidly. I throttled down and dropped into fourth at 8500rpm, which the bike didn’t like at first, although it seemed as torquey as a V-twin. I snatched another look backwards, the Kawa was 15 yards behind, the Bonnie well out of it. As the Kawa caught up, we got the green light and cruised at 70 to 80mph, wary in case the Triumph owner tried it on again. But he didn’t, when the road split up the Kawa owner (who would have been first if he’d been solo) waved happily but the Bonnie owner tried to ignore our goodwill.
When I arrived home I sat slurping coffee and looked at the Yam cackling with glee (the Yamaha was, honest, that wasn’t a grammatical error). It really had performed incredibly well against what had been some pretty hefty opposition. I remember thinking it’s done it again, because it seemed that the Yam’s main function was to exceed all expectations of it. It was a bike which deserved one’s greatest respect, yet I would, if given the chance, have swapped it there and then for a Kawasaki 500. Traitor! Funnily enough, last year I revisited the area, finding that I dare not ride my Kawa 500 at more than sixty down that same road.
The YR series bikes are rare, these days. The YR3 is a rather beautiful 60s twin which has an extremely nice mellow exhaust note. The YR5 came at first in orange and white with seamed silencers that dipped to miss the rear wheel axle. The orange and black YR5F followed, accompanied by the much more popular YDS7. These shared many identical parts, although you could just change the 250 to 350 by swapping top ends.
Although there are still parts about, they’re hard to come by, whereas there are simply tons of RD bits and plenty of cheap bikes. Buy one to run and a couple for spares. Cheaper than buying one Kawasaki 500, believe me. But if you get a good one, I’m sure you'll like it. You might not be crazy about it. Short of money, I took my Yamaha off the road in 1976, intending to return to it in a couple of months. Now it is in a barn, covered in a thin layer of rust, waiting to be restored just like people used to do with Indian V-twins, et al. [It has certainly made it back to the road by some means, XCA42K shows as taxed on the DVLA computer as I write - 2022 Ed.] A shame to waste it, but at the moment I am pouring all my available money into attempting to run an extremely undeserving Kawasaki 500, so the Yamaha must wait.
A lot of bikes these days are tagged classic. A much overused term but one which might appropriately be applied to any of the Yamaha 250 to 400 twins. It’s hard to adequately define their place in the order of things - favourites are established by varied means. They could be in anyone's top ten best ever; there again, they might just rate a footnote in history. Familiarity and the passage of time seems to have turned these old street burners into worthwhile propositions. Buy that cheap runner and see what happens.
Roger Ledsham