The Yamaha RD350LC Widowmaker That Trained A Racing Generation
All the way through the 70s, two-stroke motorcycle dominated racetracks all over the world. Several ambitious European brands came and went seemingly overnight, but it was in this decade that the Japanese brands (except for Honda) took to two-stroke technology like ducks to water. Yamaha, in particular, were doing some amazing things on track with their TZ race bikes, and it was only a matter of time before we saw this race-proven tech trickle down into some road bikes.
The RD350LC Was An Accessible Performance Bike
Back in the early 80s, the repli-racers which dominated the latter half of the decade were still but a pipe dream. The RD350LC was about as close as it got to a race bike with lights back then, offering enthusiasts of all levels, shapes, and sizes an affordable performance bike that looked (minus the fairing) and sounded like the bikes that were winning titles back then. It was, in so many ways, the ideal bike for the time, yet it never made it to the US.
Any used examples you see for sale across the US are either from Canada, or were imported directly from Japan at a later date. US emissions restrictions were particularly hard on two-stroke bikes, and Yamaha made the (arguably wise) decision to rather import more two-stroke dirt bikes which were not subject to such testing, and were selling like hotcakes at the time. Today you will find project bikes for next to nothing, but a solid runner will set you back around $5k, while pristine restored examples will cost more than $10k. Which is a lot for a bike that was initially more of a working-class hero.
A 350cc Liquid-Cooled (LC) Parallel-Twin With Crazy Powerband
Power: 44 Horsepower*
The TZ250s and 350s from the 70s were exceptional class racers that had won several top-level races around the world back in a time when several GP riders would ride in multiple race classes. These racing bikes were at the bleeding edge of performance back then, and had a hand in the development of the road-going RD350. While the engine itself is more closely related to the previous air-cooled model, the addition of liquid-cooling certainly helped improve performance. By modern standards, its peak power of 44 horsepower at 8,500 RPM (some publications claim more, but Yamaha only claims 44) might not seem like much, but the way it all arrives at once certainly makes it feel more powerful than it actually is, and it also makes the bike something of a handful to ride for the uninitiated. Below 6,000 RPM, it is pretty much gutless.
Old Two-Strokes Are Maintenance-Heavy Machines
This kind of narrow powerband is just the nature of the high-performance two-stroke beast, but is also only one part of the problem. In an effort to ensure the power does eventually arrive, it needs to run pretty rich. You can easily lean out the mixture, but this will have an adverse effect on overall performance, and it might bog down at low RPM. So, even though it is a small displacement motorcycle, it certainly is not the most economical motorcycle. Running costs for these bikes will not be insignificant, because they will also be going through a fair amount of two-stroke oil as well as fuel, and, unlike four-strokes, will require a top-end rebuild every so often. Parts for such rebuilds won’t be readily available, and this kind of thing needs to be factored into the initial purchase price.
The RD350LC Is A Fun, Attainable Classic
Classic motorcycles are often put on a pedestal of sorts, but they are not all meant to be stored in a hanger somewhere. Some bikes are meant to be ridden, and while these little two-strokes are certainly an acquired taste, once you ride one you might find that it is the kind of taste you can easily acquire. There is a certain kind of thrill that goes with a bike that is a little challenging to ride, and that is exactly what you get with the RD350. Keeping it “on the pipe” is a skill, and once you master it, it will feel as though you have unlocked some form of motorcycling achievement.
While almost all of these high-performance two-strokes get lumped together as “widowmakers”, the RD350 is pretty tame compared to bikes like the infamous Kawasaki H2. It has a narrow powerband, but the power delivery is still manageable. What made it really tricky to handle back in the 80s can also be somewhat mitigated today.
At just 328 pounds (dry), this is a very light motorcycle, so there is no denying that it can be a little twitchy at speed. This was exacerbated by what is a relatively rudimentary steel frame, and soft front forks which had a propensity to dive under hard braking. A combination of all these factors could conspire against you mid-corner if the power arrived at the wrong moment. While there is no affordable solution to the chassis problem, modern tires, a refreshed braking system with modern brake pads, and refreshed forks will transform the bike into something significantly more manageable.
YPVS Takes It Up A Notch
By 1983, the model got its single biggest update with the addition of the Yamaha Power Valve System (YPVS). For some markets, the name was also changed to the RZ350, and could also be had with a full or partial fairing like the bike pictured above. Although the power valve was not a new concept, and a mechanical version had been used on Yamaha dirt bikes, the RZ’s power valve was electronically operated. It helped boost power lower down in the rev range by partially closing the exhaust port, then once the revs climbed, it would open up for maximum performance (think variable valve timing, just for two-strokes). Once you got “on the pipe”, its 50ish horsepower would still hit you in a pretty aggressive manner.
A few short years later, several affordable four-stroke sport bikes were introduced to the market, and even though they were still more pricey than the RZ, most buyers were more than willing to fork out the extra cash. All these four-stroke sport bikes made their power in a more predictable manner, making them a degree more approachable no matter how much more power they actually had. Emissions restrictions were also clamping down on these oil-burners, and a combination of these factors effectively brought the curtain down on the two-stroke era.
Sources: BaT and Yamaha Global
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