YAMAHA 2-STROKES

Yamaha YA-1

The YAMAHA YA-1 is the first motorcycle produced by the Yamaha Motor Company. It was made from 1955 to 1958.

In the early '50s, after having to replace the factories for the production of musical instruments, which were severely damaged during the war, Yamaha was facing the industrial conversion of factory machines, with mechanical precision, that had been used during the war for the production of fuel tanks and propellers for aircraft of the Imperial Navy, such as the A6M Mitsubishi Zero and the biplane Yokosuka K5Y.

Equally to all European countries, including Japan after World War II, the motorcycle had become a widespread means of transportation, thanks to constructive simplicity and economy of purchase and use. Japanese motorcycle production had increased from 10,000 units in 1950 to 750,000 in 1954, with over 100 domestic manufacturers.

Due to strong expansion of the Japanese domestic market, Yamaha Motor Co. decided to convert to the production of motorcycles, and found in the beginning the need to grapple with high specifications for customers with elite, rather narrow needs, especially in view of the reduced numbers of production potential.

It was the beginning of 1955 when they presented the YA-1, a motorcycle built with particular attention to materials and assembly, enhanced by sophisticated engineering, strongly inspired by the contemporary model DKW RT125, and driven by a 125 cc two-stroke, single cylinder engine.

In January 1955 the Hamakita Factory of Nippon Gakki was built and production began on the YA-1. With confidence in the new direction that Genichi Kawakami was taking, Nippon Gakki founded Yamaha Motor Co., Ltd. on July 1, 1955 and made Kawakami the new company's first president. Staffed by @ 275 employees, the new motorcycle manufacturer built about 200 units per month by the end of 1955.

That same year, Yamaha entered its new YA-1, known to Japanese enthusiasts as Akatombo,or the "Red Dragonfly", in the two biggest race events in Japan. They were the 3rd Mt. Fuji Ascent Race and the 1st Asama Highlands Race. In these debut races, Yamaha won the 125 cc class. The following year, the YA-1 won again in both the Light and Ultra-light classes of the Asama Highlands Race. The YA-1 established a reputation as a well-built and reliable machine. The racing successes helped boost its popularity and a second machine, the 175cc YC-1 was in production by April 1956.

Immediately used in competitions, YA-1 won victory in the prestigious race in ascent of Mount Fuji, held in July 1955, demonstrating that the model was free from defects, except for its price of 138,000 ¥. The equivalent to about 40,000 € in 2005.

Competition models were often painted the same orange-red as military aircraft, and the YA-1 was dubbed "aka-tombo", (in English, red dragonfly), like the famous biplane trainer of Yokosuka.

This beautifully minimalist Yamaha Y125 is patterned after the first Yamaha two-stroker. The YA1 was a real sweet looker in her own right, and it looks like this little four-stroke can carry the torch proudly!

Yamaha RD350

Here's a great summing up of the glory days of Yamahas' fabled RD350.

"Before we had any clue about the myriad dangers of triple cheeseburgers, saturated fat, unburned hydrocarbons and street-going two-strokes, there was the RD350. Dirty, foul-mouthed, deliciously quick and relatively affordable, it was a Giant Killer.

Anybody old enough to read a bike magazine back in '75 knew it was true.

From the first '73 RD350 to the last 1975 RD350B, Yamaha's overachieving pocket rocket humiliated triples and fours packing over twice its 347ccs on racetracks and backroads all over the planet. Back when bell-bottoms were cool and Harley's weren't, most anybody's big-bore multi roasted the RD in a straight line. Horsepower was cheap, and any fool could twist a throttle.

But motorcycle handling was still an oxymoron in Japan...except at Yamaha. When seventh-morning services convened at the shrine of the divine apex, street or track, all bowed to the RD. For the proletarian canyon commando, laying down $3000-plus for one of 50 1974 750SS Ducatis was like Led Zeppelin playing the next freshman/sophomore mixer: very bitchin', and highly unlikely. Kawasaki's very fast, very large Z-1 wore a $1995 price tag. But a 1974 RD350 sold for $908: Moet Chandon on a Schlitz budget. Racetrack handling for the masses.

The RD350's street roots stretch back to February 1967, and the YR1--Yamaha's first street-legal 350. But the 1970 R5 350 drew a straight line from brand Y's TR production racers to the street.

Fast forward from the YR1 to the mercifully cleaner lines of the 1970 R5 350. Adding new seven-port, reed-valve cylinders and a few other refinements turned the '72 R5C into the 1973 RD350. Now we're on to something. Even in '73, RD styling was still parked somewhere between tawdry and garish. But 0.010-inch thick spring steel reed valves between 28mm carburetors and the new, seven-port cylinders made all the difference. The 347cc RD twin used classical 64x54 bore and stroke numbers to spin out about 35 horses at 7500 rpm.

Pushing 352 pounds fully fueled, Motorcyclist's admittedly rough-running 1973 test bike covered the quarter-mile in 14.48 seconds at 89.8 mph. Cycle magazine's RD ran closer to its potential with a 14.12-second/93.2-mph blast. Those numbers were underwhelming alongside beasts like Kawasaki's 12-second triples and fours. You could fluster 'Vettes and Hemi 'Cudas roosting away from a light, but the RD wasn't a dragster.

Agile, light, simple and reliable (see "Yamaha RD350/RD400: Charting the Changes" sidebar, p. 64), the RD would take you from work and back Monday through Friday with Clark Kent gentility, offering only the odd oil-fouled B8HS spark plug in protest. It was smooth and comfy enough for freeway travel, allowing gas station pit stops at 100-mile intervals; the thirsty little twin's 3.2-gallon fuel tank called up reserve every 70 miles. Two quarts of oil flowed through the Autolube system every 500 miles or so. But turn up the volume and fuel mileage fit the bike's Bad Boy image. Figure about 26 miles to the gallon if you were loose with the loud handle.

From its birth until Yamaha's FZR400 took over in 1988, the 350 Yamaha two-strokes were pretty much the dominant tool for 400-class production racing on the cheap. San Francisco Bay area RD aficionado Dale Alexander remembers the 350 as a potent, reliable tool once it was set up correctly. "I could race my RD all season for the price of a new FZR400," he says. Before moving on to TZ Yamahas, Formula 1 Suzukis and such, Thousand Oaks, California's Thad Wolff routinely clobbered all comers in the 1979 AFM 400 production title aboard a very rapid RD375 (extra displacement courtesy of TZ750 pistons in chromed bores, spinning a TZ250 crankshaft). "The only competition for a well-set-up RD was another RD," Wolff remembers.

Even without all the good stuff, nothing got through a tight set of corners any quicker than a savvy RD pilot. Motorcyclist's November 1974 test of the RD350B said, "...in everything but all-out acceleration, the Yamaha 350 will probably outperform just about anything on the market in box-stock trim." We griped about hard grips, a little too much engine vibration and footpeg mounts that eroded rapidly at maximum lean. Otherwise, the RD was a gem.

Even a pristine example of the breed (like the 1975 RD350C pictured) will underwhelm derrieres calibrated to current four-stroke sporting weaponry. Still, novelties like really light weight and the two-stroke's rush of dirty little explosions every time a piston heads earthward ("Dang the ozone layer, Scotty, give me acceleration!"). Eco issues aside, it's a deceptively quick little beast to ride.

The RD looks tiny by 1996 standards because it is. Even so, nice flat bars and a seat to match keep six-footers comfy for 100 miles or so between fuel stops. Twenty-year-old suspension bits feel...well, about 20 years old. The little 350 still corners on rails, even if it does wallow and grind its low-slung undercarriage at relatively mild lean angles. But keep rowing the cliche-smooth transmission's six tightly bunched ratios to keep the hydrocarbons burning between 6000 and 8000 rpm and the RD flat out roosts--60 mph arrives in less than four seconds. Even through the tastefully muted stock mufflers, the weed-whacker-on-benzedrine exhaust note is pure heaven.

The RD was the official bike of working-class curvy road cognoscenti in the mid-'70s. As Yamaha product planner Ed Burke says, "The RD was a cult bike if there ever was one." All it took to initiate membership was that velvet shriek rising into your Bell Star. Once you knew what it could do to a perfect road on a perfect morning, nothing else was even close. But all good things must come to an end. Neither the cleaner, more "civilized" 1980 RD400F or the liquid-cooled RZ350 (a story for another day) of 1984 could win the war against progressively faster, more sophisticated heathen four-strokes. Riders demanded bigger, faster bikes. The EPA wanted cleaner ones. The handwriting was on the wall. The RD350 begat the RD400 in 1976, and by the end of 1980 the 400 disappeared from Yamaha showrooms as well.

Modern prototype RD350

Yamaha RC5/350

Yamaha RD500 as seen and read on the International RZ/RD 500 Owners Group

True Confessions Of a Two-Stroke Junkie

By Tom Fortune

I remember the day like it was just yesterday: The day I first laid eyes on an actual RZ500. Not just a picture, mind you, but the real thing. It was back in June of 1984, in Carlsbad, California. The American round of the 500cc motocross World Championship used to be held the at the local motocross track, Carlsbad Raceway. On Saturday morning, before the qualifying rounds, they held tech inspection for the bikes in a local hotel parking lot.

It was a chance to see the exotic factory GP motocross equipment up close, and meet some of the riders. I had recently bought an '84 Kawasaki ZX 750 Turbo, and thought I'd ride it over to check out the tech inspections. First off, you have to understand one thing here. You see, I grew up riding two strokes. Had ridden everything from 1960s era twins to 1970s era triples to the latest RZ350s of the early 1980s. Loved two strokes. And I had developed a fascination with Grand Prix two strokes in particular. Both road-race and motocross. Kenny Roberts' epic battles with Freddie Spencer in the 1983 World Championship had made Yamaha's newest GP racer - a V-Four, 500cc two-stoke - the focus of my attention.

At this point in time I had only seen a brief news blurbs about the possibility of Yamaha producing a street version of Roberts' 1983 GP bike. Wouldn't that be exciting, I mused. But as I strolled through the parking lot looking at the motocross hardware that sunny June morning, it caught my eye. Sitting all by itself, over by the hotel's main entrance, was a shiny new RZ500. I couldn't believe what I was seeing! I was drawn over to it like a magnet.

Hot Damn! The ultimate road-going two stroke!

I spent the next hour or so checking out every little detail of that bike. 'What a machine,' I thought, 'a real beauty. An honest-to-goodness GP bike that I could ride.' I remember uttering to myself over and over 'I have to have one!' Soon, though, it was gone. Ken Clark, who at that time was head of Yamaha's U.S.racing program, came out of the hotel, jumped on the RZ, kicked it over, and rode away in a cloud of blue smoke. The bike must've been something Yamaha had given him to ride around on while he was in town for the motocross GP. Nice ride!

I was totally consumed with passion. I completely forgot about finishing my tour of the parking lot, and went over and got on my Kawasaki GPz750 Turbo, started it up, and headed back home. Riding the Turbo just wasn't the same after that. Within a month it was sold, and my order for an RZ500 was placed. Six months and many phone calls later my dream bike arrived from Canada, still in the crate. After some tense moments with the customs officials ('Hey, fellow, this bike's got kilometers per hour on the speedo. Supposed to have miles per hour...'), I brought the bike home and quickly assembled it, fired it up, and took it out for that first ride. It immediately won my heart as my lust turned to love. Still own that bike. Roadraced it too. I've acquired two more RZ500s since then, and for me, they are still the ultimate road-going two-stroke.

Photo above by Tom Fortune

YAMBITS. A great story about a company.

Story by Classic Motorcycle Mechanics.

British iron has been well catered for over many years and numerous companies supplying those vital parts started off with a lorry load of NOS that no one else initially wanted. As these original parts supplies dried up it was inevitable that pattern items would become the norm and this approach has kept many 1950s and 60s machines running a lot longer than anyone might reasonably have thought. Therefore it was both logical and inevitable that the same scenario would ultimately be reprised with Japanese machinery, after all its undoubtedly the future of the classic scene.

All of the above is fine in theory but to carry out such an exercise you need to careful select your target market, do more than a little homework and be prepared to invest time and potentially large sums of money before you even think about seeing a return. Choose iconic machinery such as Kawasaki H1/2 or the Z1 and you’re unlikely to go wrong, ditto Yamaha’s seminal XS650 in all its various guises; in fact with the examples cited it’s almost possible to build a complete machine from newly made parts. With any of these machines you’d have to work quite hard to get it wrong but what if you chose to spread your net wider and take a punt at pretty much any Yamaha two wheeler made since 1975? Much riskier. Yambits, probably one of the most successful parts specialists out there and a perfect example of turning a hobby into a business, has done exactly that. Owner and frontman Dave Newboult’s background as a qualified mechanic working on the plant fitting of heavy machinery meant he was as adept at twirling spanners on big industrial machines as he was on his Fizzes and RD250s. Subsequently building racing cars and simultaneously selling pattern parts for eart moving equipment must have subliminally established the foundations of a bike parts business. So when a change of circumstances dictated Dave needed to work from home it was almost a no-brainer.

The career change was a perfect match to the skills set already acquired; all that was lacking was legion upon legion of parts books and countless hours of cross referencing. This acquired knowledge has proved to be the key behind Yambits; the in-depth knowledge of which parts fit which machines, how Yamaha’s supersession’s work and when to commission parts from alternative sources. As Dave points out: “We obviously have competitors but the bulk of them choose to only replicate a few fast moving lines and often the parts they sell are only approximations to the real thing, we aim to get the quality, performance and fit as good as or better than the original.”

Knowing what is likely to sell and the potential volumes involved are fundamental in making sure your economies of scale add up. There’s no point in commissioning tooling for parts if you end up with the most of resultant components gathering dust on the shelf; getting a prompt return on your hard work, research and investment means you can reprise the exercise over and over again. A perfect example is the total wipeout of the company’s stock of recently introduced front brake callipers long since unobtainable from Yamaha.

Always corroded, inevitably sporting a seized piston and often boasting a stripped bleed nipple thread, Dave and the team knew the part was needed by customers but were shocked at the way they sold out so quickly. Another batch is being produced and in the meantime you can still buy individual service components but it just goes to show many owners simply want to unbolt a problem module and install a functional, working, alternative. The market has moved on and many of the owners simply don’t have the time, or the inclination, to rebuild sub-assemblies. However, should you wish to pass a quiet Sunday in the workshop fettling your own calliper the parts are readily available from stock.

The level of research and detailed attention the market components receive is perfectly illustrated in the replacement calliper sealers due to come on line as we go to press. Alternative aftermarket seals have been available for some time but these are often little more than size specific O-rings and sometimes annoying feature minute moulding flashes which variously cause fluid leakage and/or fitment issues. Yambits’ new parts are the correct rectangular profile carefully parts on by a special lathe tool. They feature a purpose made, extruded rubber polymer that’s dimensionally accurate. If this sounds like a cottage industry approach, know that this is exactly how the top UKL names had their equivalents made en masses back in the day. Pattern of aftermarket parts often get a bad name purely because a small segment of the items of the items available are poor quality, shoddily made, copies or fakes. If you’re going to commission replica parts you have to be able to control every attribute of your new component and back the also-ran rubbish.

Sitting ready for a lucky (or is that unlucky) owner is a complete YPVS 350 crank ready to take the place of one destroyed last weekend during that impromptu spring; not something you’d expect your local Yamaha dealer to have in stock. Sometimes it’s the nadgery little odds-and-sods that hold up a rebuild and again it’s the company’s attention to detail that pays off here delivering hard-to-find items that finish a project for the customer and turn in a profit. The little wire spring clips that secure fuel pipe to taps and carbs have variously been impossible to obtain of late, likewise the peculiarly translucent pale pink overflow pipe used on float bowls; there’s no guessing who’s had these made up ready to fit.

The end result is that what started off as a fledging parochial business run out of a kitchen has become a global success. Sending parts to Europe is a daily exercise, with America now becoming a substantial market as our cousins across the pond wake up to the classic Jap scene. South Africa, Greenland and the Cook Islands also appear on the despatch sheets along with Japan, which is nothing if not ironic. Perhaps the most dedicated customer to date is the American oil pipeline engineer who is restoring a bike in a container that gets moved across vast plains of Russia. Each time he gets a new semi-permanent home he emails in another order and the team get his parts out before he moves on again.

There’s no such thing as a typical Yambits customer; Dave’s daughter Hollie does a lot of the parts picking and purchasing and she knows many of the customers by bike and name. Although a lot of the parts go to people restoring there’s a very strong customer base that simply wants parts to keep their bikes on the road and this sees large volumes of service items being sold. Camchains for the later four-strokes, filters, gaskets, fork seals and the like are all fast movers and it’s to the customer’s benefit that everything in stock is at an OEM, or above, level or quality.

With a registered customer base exceeding 75,000 you’d be right to assume the business is both successful and very well established. The only real issues to getting the right parts sent out are potential misinformation and a lack of model knowledge on the owner/customer’s behalf. As the staff point out, despite what people might believe, the country isn’t peppered with rare Yamaha prototypes. Photographer Joe and I are more than a little surprised when some Yamaha TY80 parts are laid out for us to inspect. The pattern chain guard looks pretty much perfect to us, even down to the colour of the metallic silver paint. The seat pad similarly looks just like an original part and we ask how long items such as these to arrive from China. Our rash assumptions are blown completely out of the water when it’s explained both items are made in England.

Sourcing components from the UK might sound either naive or even a touch jingoistic but there are hard0nosed businesses motives behind such decisions. Source from outside the EU and you’ll be paying import duty that will have to be passed on to the customer, the further away the supplier is the longer the goods take to get to the UK and this ties up money that could be better spent elsewhere. Deal with an anonymous metal bashing shop somewhere in China and see just how potentially frustrating an email exchange on quality, fit or delivery might be. All of Yambits’ suppliers are effectively and rigorously assessed to ensure they deliver quality before anything else.

As Dave slides an original RD400 headlamp bracket across the desk towards our camera along with two prototypes we probably already know better than to suggest anything other than a virtual Made in England sticker; these dead ringers will be coming from just down the road ready to return many a modified machine back a little closer to how Yamaha intended. Of course stuff does come in from SE Asia but it’s either from the OEM suppliers out of Japan or from Taiwan where national pride and a Japanese-type mindset ensures both quality and dimensional accuracy. As if to prove a point we open a box full of replacement LC250/350 inlet rubbers from the same supplier Yamaha used and they are as Japanese as sushi or sake. And on the shelf above there’s a box of aftermarket headlamps from Taiwan proudly bearing a legend stating they are not Chinese copies.

If that wasn’t irony personified, Dave has also experienced customers telling him where he can get specialist parts replicated. A sizeable chunk of the customer base are over 40 and many have been working in the manufacturing industry all their lives so they know where to get things made and pass on the details; customer loyalty probably doesn’t get much better. From identifying a market need to having the first replicas ready for sale can take up to 12 months but if it’s doable it gets done. The commercial rewards that come from the research and effort developing both the products and the suppliers scores highly with the team; you can’t do this sort of stuff repeatedly unless moral is high.

Being told something is plainly impossible only seems to galvanize the collective effort to replicate a long obsolete part; if it can be made, it will be made. The only exceptions are items that bear an obvious trademark; to replicate either a logo or name would be tantamount to counterfeiting.

Another area that is unlikely to see development is exhaust systems where the economies of scale don’t stack up due to the cost of press tools versus the likely volumes of sale. Even if it was commercially viable, customers at the restoration end of the market buyers would want to see Yamaha’s famous part numbers stamped on the end cans and again this wouldn’t go down well back in Japan. Frames and tanks are similarly not viable and you are unlikely to see Yambits move into wheel rims or fork stanchions simply because there are other people out there doing them in huge number. Anything else, however is fair game and this is obvious when we start looking around the closely packed racks of components.

Sitting ready for a lucky (or is that unlucky) owner is a complete YPVS 350 crank ready to take the place of one destroyed last weekend during that impromptu spring; not something you’d expect your local Yamaha dealer to have in stock. Sometimes it’s the nadgery little odds-and-sods that hold up a rebuild and again it’s the company’s attention to detail that pays off here delivering hard-to-find items that finish a project for the customer and turn in a profit. The little wire spring clips that secure fuel pipe to taps and carbs have variously been impossible to obtain of late, likewise the peculiarly translucent pale pink overflow pipe used on float bowls; there’s no guessing who’s had these made up ready to fit.

The end result is that what started off as a fledging parochial business run out of a kitchen has become a global success. Sending parts to Europe is a daily exercise, with America now becoming a substantial market as our cousins across the pond wake up to the classic Jap scene. South Africa, Greenland and the Cook Islands also appear on the despatch sheets along with Japan, which is nothing if not ironic. Perhaps the most dedicated customer to date is the American oil pipeline engineer who is restoring a bike in a container that gets moved across vast plains of Russia. Each time he gets a new semi-permanent home he emails in another order and the team get his parts out before he moves on again.

There’s no such thing as a typical Yambits customer; Dave’s daughter Hollie does a lot of the parts picking and purchasing and she knows many of the customers by bike and name. Although a lot of the parts go to people restoring there’s a very strong customer base that simply wants parts to keep their bikes on the road and this sees large volumes of service items being sold. Camchains for the later four-strokes, filters, gaskets, fork seals and the like are all fast movers and it’s to the customer’s benefit that everything in stock is at an OEM, or above, level or quality.

With a registered customer base exceeding 75,000 you’d be right to assume the business is both successful and very well established. The only real issues to getting the right parts sent out are potential misinformation and a lack of model knowledge on the owner/customer’s behalf. As the staff point out, despite what people might believe, the country isn’t peppered with rare Yamaha prototypes.

Yamaha didn’t shake down the LC350 lump in an early XS250 chassis; the bike is almost certainly a backyard hybrid. All UK supplied bikes had matching engine and chassis numbers and if a customer’s bike has an earlier engine ID it’s almost guaranteed the lump is from another machine. Engines with only a model ID stamped on the cases are similarly not rare of special; Japanese market cases often never carried a full engine number. The key piece of information the Yambits team needs to establish what bike it is supplying parts for is the chassis number, everything else can, may or has the potential to be changed or altered over the vehicle’s life. Caroline points out a customer may get in contact saying they have a V-registration XS250. The first question is; please give me the frame or engine number. Do you want the parts to fit your bike or your logbook? There are only so many hours in the day and reluctantly Yambits has now stopped taking telephone orders. Dave and Caroline’s offices are strewn with samples to examine and source so they’re adopting the mantra – don’t work harder, work smarter. As Dave points out: “If every customer told me his motorcycling life story I’d never get a thing done. There are some fascinating people are truly amazing anecdotes out there but we simply can’t absorb them all.” Having successfully recruited new IT manager Josh, the Yambits website has simple functionality that anyone can use. It’s constantly tweaks and updated with new parts to serve its customers on a daily basis. If one of its older customers at 73 can navigate the website it shouldn’t be too challenging and a new ‘Bike Identifier’ service has also been recently added to further help owners.

Dave’s other (and many we say infinitely more attractive) half, Caroline, has been a key player in the business utilising her data entry skills to scrutinise the parts books and fiches. Thanks to her diligence and some very late nights it’s possible to know how many models will utilise a common swinging arm bush/set of fork seals/head bearing sets or whatever else you might need. It’s this intimate and innate knowledge spread over more than 680 specific models that allows Yambits to offer such wide ranges of parts and know with the utmost confidence that they’ll fit. Even if the shop door closes at 4.30pm there’s always another series of part books or online fiches to pore through adding more precious information to the database. Furthermore, by knowing which individual components will fit other models it’s possible to offer a comprehensive range of service kits by combining the various components without proliferating unnecessary part numbers or stock. Running a parts business is not just about buying and selling outsourced items; managing the inventory and investing time in R&D means prices stay as low as possible which has to be good news for us end users. Yambits has an excellent team of staff who are all committed to getting the job done right. The future for them looks both interesting and challenging, there’s always something new coming on stream. As we’re packing up to go there’s an order in for the newly produced ally fork tube top nuts and Dave is excitedly working away on a nascent specialist segment for the legendary TZ racers, so life is unlikely to be dull for the foreseeable future.

As that unobtainable NOS dries up or gets priced out of reach it would be a very brave rider that suggested the future for Japanese pattern parts was anything other than rosy. We can’t help but wonder why no one seems to have jumped at the opportunity to emulate Yambits with Suzuki, Honda or Kawasaki; there’s unquestionably a substantial market out there

Thanks to YAMBITS and Classic Motorcycle Mechanics for this!