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One-Eighty: 1989 Yamaha TZR250 3MA for Sale

It's been a while since we've seen a Yamaha TZR250 3MA for sale, and the bike is both very rare and also a sportbike, so we're posting this one, even though it isn't in perfect condition. I'm a huge fan of this particular iteration of the TZR, because of course I'm a fan of the weird, slightly less-than-successful version of any bike. With competition very fierce in the 250cc sportbike class and specifications so similar, Honda, Suzuki, Yamaha, and occasionally Kawasaki were all looking for a competitive advantage. The bikes all had aluminum beam frames, liquid-cooled two-stroke twins, and power valves to boost midrange. Light weight meant incredible agility and the triple disc brakes were almost overkill for the 300lb machines.

Although two-stroke engines are very compact, routing the bulky de rigueur expansion chambers meant design compromises: the typical quarter-liter solution meant asymmetrical "banana" style swingarms that looked cool and allowed the expansion chambers to tuck in close to the centerline and maximize cornering clearance, but added weight.

Yamaha had a different idea. Why not flip the cylinders of their parallel twin around 180° so that the carburetors were at the front and the exhausts exited toward the rear? Since two-strokes lack camshafts or valvetrain, this was pretty simple to do for the 3MA version, and meant there were no worries routing the exhaust and expansion chambers around the bike's lower half. Instead, they went straight back and out through the tail, creating a slight bulge in panels just below the seat.

The concept was sound but the bike was produced for just two years and is generally considered a failure, although its reputation for mechanical unreliability is apparently a bit of an exaggeration. It was light and handled brilliantly, but the reversed-cylinders offered no real advantage. A failed experiment, the bike was only officially sold in Japan, although the bike did find its way to parts of Europe as a parallel import.

This little TZR is a complete machine and appears to be original, but is a little scruffy around the edges, although it's hard to tell from the pics. I'm seeing the typical corrosion and discoloration you'd expect on a Japanese bike of this era, especially one that likely spent it's first few years in the salt air of its homeland.

From the original eBay listing: 1989 Yamaha TZR250 3MA for Sale

1989 Yamaha TZR 250 3MA, no reserve
New tires, chain and sprockets, carbs rebuilt, fresh service
Very low kilometers, runs good, aftermarket exhaust chambers, bodywork is OEM
I can send running video, call me or text me 954-809-8596
My name is Mike

Hi, Mike! This isn't my favorite color combo for this bike, but you can't go wrong with basic black. The $5,500 opening bid is probably in the ball park, but I wonder what the reserve is. TZRs are rare, but seem to generally be less desirable than NSRs. Personally I love the look and general weirdness of the 3MA, but there was no performance advantage for the backwards cylinders, and I've read that parts are harder to source than for earlier parallel twins or later 3XV v-twin TZRs. Basically, it's a cool bike, but it's the oddity and style that appeal most, and this one is a runner, but in need of a bit of cosmetic TLC.

-tad

14 Comments

  • Nice. This would be great for an RZ500 engine swap.

  • Wheels would originally have been white. Seat tail section is either not installed correctly, or pipes/subframe is bent. Silencer tips should be centered in those openings (note too that the taillight assembly is not centered in the cutout either. I’d want to see what this looks like with the rear bodywork removed.

    These are fun however (and not as cramped as some of the other manufacturer’s 250’s). Owned one while USAF stationed in Greece (traded a RG400 for a 0-mile example…).
    Much more difficult to derestrict than a NSR is my understanding, and the 18″ rear wheel limits rubber options. Swapping in a 17 is do-able, but some machining is needed.
    Nice toy just the same.

  • I love this bike, this is my second favorite 250 race replicas. I used to “race” against those hell of a lot back when I was young and stupid around the mountains of Japan. Those rear exhaust TZRs are slightly finicky, for sure. My memory serves that they tend to foul plugs rather easily, doesn’t like stop and go more than any of its contemporary 2 stoke 250s. By the way, the reasoning behind the rear exhaust is incorrect, it’s not for cornering clearance reason. It was done based on a philosophy that if the engine could breathe in and spit out in straight line, instead of making many turns and twists, they could achieve better control over the power delivery. According to Yamaha, it is indeed the case, except that apparently it made the settings pretty severe. Also, against the conventional v-twin, parallel twin just didn’t make enough power. When the TZ went v-twin, so did TZR. You gotta follow the race bike to keep them fresh to us young, rather not so smart, customers.

    • That’s interesting. I’m aware that reversed-head configs usually boast some sort of airflow advantages, since the carbs are mounted in a location where they can get great access to cool, fresh air, but didn’t see anything like that being claimed for this model. I think in previous posts on the 3MA I’d mentioned it as a possibility, but good to know that’s what it was really about! I’m sure I’ve seen the cornering clearance advantage mentioned, but that could very well just be a side-effect of the setup that was meant to “improve flow” like you mention.

  • I just love the write up….talk about short and sweet. Hi Mike. HAHA. Too funny!

  • Tad – Why not flip the cylinder head of their parallel twin around 180° so that the carburetors were at the front and the exhausts exited toward the rear?

    Reversing the cylinder head on a two stroke does nothing.

    • You say it “does nothing on a two-stroke” but I’d guess professional engineers would disagree with you: experiments using the format have been around for a long time for both two and four-stroke motorcycles, and reversed cylinder heads have been seen on bikes much more recently than the 3MA. I’m not an engineer, but a bunch of folks who get paid to design stuff think it’s worth looking into. Obviously, the design never really caught on, so apparently real-world advantages are minimal. According to j.b.21, Yamaha at least believed that there was a benefit, but a class switch to v-twins made the reversed-head design a developmental dead-end.

  • The belief was that by straighten out the airflow, that it can breath better for one. And not only that, because the expansion chambers don’t need a packaging compromise, so the idea was that the design would provide more control over the power delivery. This actually was a lengthy development for Yamaha, first tested I believe in the later part of 1987, then full production for privateers for 88. Of course, as you know, TZ was equivalent of Honda’s RS250, basically a GP racer for customer team. This is by the way pretty odd if you think about it, because Yamaha’s GP machine, YZR250, was V-twin from get-go in 85, but TZ would remain parallel twin till basically the last incarnation, which street-going TZR would follow, instead of YZR. Frankly, this was very bizarre from marketing point of view. Not that we cared, but still…

  • Yamaha consollidated the customer & factory development trajectories in 1991 – so the TZR, TZ and TZM all shared some components and design.

    The reason Yamaha kept the YZR and TZ development trajectories separate was to allow for a more cost effective and thus higher volume of customer race 250’s to be sold/supported and raced. TZ’s out numbered RS’s on the grid at least 2:1.

    YZR tech did trickle down to the TZ, but they shared no components – well, not entirely true – they shared axles, steering stems and footpegs and wheel bearings… 😉 The TZ and TZR however shared many components. Some even shared part numbers.

    The TZ250 was always cheaper than the RS250 and if you notice always shared parts with other Yamaha lines and had parts available for a longer time period – where as the HRC RS250W/NSR250R/RS250 trajectories did parallel each other resulting in higher costs and much shorter spares life cycles. They shared little other than layou with the NSR street bike.

    Try source a or rebuild a 1987 RS250 crank… now do the same exercise with a 1987 TZ250. 🙂

    • Yeah, I’ve read a couple articles about people who own ex-race two-strokes and it sounds like it would be a whole separate hobby, just to keep one running. And just imagine trying to keep an NSR500V on the road!

  • Pat – Reversing the cylinder head on a two stroke does nothing.

    Tad – You say it “does nothing on a two-stroke” but I’d guess professional engineers would disagree with you:

    Pat – Ok name one. Seriously reversing a cylinder head on a 2 stroke does NEXT to nothing. Do you even know what a 2 stroke cylinder head looks like?

    • Really? All that because I mis-typed and wrote about the “head” instead of the cylinders themselves? I come from a four-stroke background and think that way, but yeah, I know what two-stroke heads look like. I think you probably know that though. You could have just pointed out my mistake, since then I’d have simply said, “Ooops. Duh. You’re right: I’ll go fix that.” On that subject, there’s a great video running around Youtube where someone made a cylinder head out of some clear material and videoed the bike running.

  • Actually, reversing a water cooled 2 stroke head can do something… besides the bolt pattern maybe not working in reverse – lets assume it was a symmetrical bolt pattern, water flow to and from potential hotspots be different if the barrel is not reversed as well 🙂

    And reversing the barrels places difference piston skirt/barrel loads on different sides and different bearing loads etc.

    I still have a reverse cylinder 421cc RZ350 project under the bench waiting to go into my 3MA 🙂

    • Much as the contrarian in my likes the weirdo tech, I’d be okay swapping a more serviceable engine into a 3MA, as long as it kept that gorgeous frame.

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