Yamaha XJ650 Seca
Years produced: 1982
Claimed power: 48hp @ 9,000rpm
Top speed: 127mphEngine type: 653cc double-overhead cam, air-cooled inline four
Transmission: Five-speed
Weight (wet): 502lb (228kg)
MPG: 47.5 (period test)
Price then: $3,099
Price now: $800-$2,000
Time has not been kind to many bikes of the late Seventies and early Eighties. For every well-known and appreciated classic, there’s a boatload of models with lousy suspensions, buckhorn bars, stepped seats and bad graphics. But there are a few less celebrated (or remembered) models out there that are still great bikes today, and the Yamaha XJ650 Seca is one of them.
The perfect mix
Like its mid-Eighties competitor, the Suzuki GS650G, the Yamaha XJ650 Seca combined a sport-tuned, air-cooled, 8-valve DOHC four-cylinder engine and shaft drive. These days, shafts are only for big bikes, and air-cooled fours have all but disappeared thanks to tightening emissions.
When these bikes were designed in the late Seventies, the motorcycle market had yet to splinter into the myriad niches we know today — though a sporting or touring stance was often achieved with styling changes. So it was with Yamaha’s 650 four. Announced in 1980, two versions of the 650 were produced: the sporting Seca for the European market and the “custom” (the term was just entering the motorcycle lexicon) Maxim for the U.S. The Maxim featured high bars, a stepped seat, a 17in rear wheel and breathing modifications including Yamaha’s swirl-inducing YICS — Yamaha Induction Control System — intakes designed to pacify the EPA. It sold well.
But moto-journalists are an inquisitive lot. Some of the U.S. motorcycling press managed to get their hands on a 650 Seca “Eurobike,” and quickly became enamored. “The Yamaha XJ650 isn’t just a great motorcycle,” wrote Michael Jordan in the November 1980 issue of Cycle Guide. “It’s the best American bike your Pounds, Francs, Lire or Deutschmarks can buy. Yamaha might not have any immediate plans to market it in the U.S., but the Euro-XJ’s performance profile perfectly suits the riding requirements of this country.”
What the journos liked was the all-day capable, ever-so-slightly sporting stance of the Yamaha XJ650 Seca compared with the sit-up-and-beg posture of the Maxim. They also appreciated the sportier suspension, sharper steering, greater power output, better brakes and increased fuel capacity.
But Yamaha had a problem: They already offered the sporty chain-drive Seca 550 and touring shafty Seca 750 in the U.S., as well as the custom-styled 650 Maxim. Should they add a shaft-drive 650 with sporting sensibilities, possibly creating mixed messages in their product lineup? They decided to give it a try.
Announced for the 1982 season, the Yamaha XJ650 Seca that arrived in the U.S. was essentially the same bike Yamaha sold in Europe, but with EPA-friendly emissions options. The moto-journos rejoiced. “Last year Europeans were treated to a sporting 650 while Yamaha delivered us the Maxim,” said the November 1981 issue of Cycle magazine. “We cried for justice and got it.”
Yamaha XJ650 Seca Specs
What was inside the Seca that made it so special? In common with the Maxim it had a sturdy, cross-braced duplex steel tube frame housing the across-the-frame four. And unlike competitor Suzuki’s 650, the Yamaha engine employed a one-piece crankshaft with plain bearings and placed the alternator and starter behind the engine to minimize width. A chain drove the two overhead camshafts, which used shim-and-bucket adjustment. A second chain drove the oil pump located in the crankcase, while a third (Hy-Vo) chain spun the alternator.
The power unit was fed by four Hitachi constant velocity carbs and lit by electronic ignition. Four-into-two headers extracted the waste gases, which exited behind the rear wheel through two long mufflers. Hypoid gears and a shaft turned the rear wheel, with the shaft housing forming the left side swingarm. The larger 18in rear wheel raised effective overall gearing, and twin 10.55in discs provided better stopping power. Ergonomic changes included a flatter seat, European bars and rearset pegs. A 5.1gal tank increased range to over 200 miles.
Performance was in line with other 650cc and 750cc Japanese machines, with a top speed of 120mph-plus and a standing quarter-mile time of around 13 seconds. Contemporary reports praised the Seca’s performance, braking, handling and long-distance highway comfort. Criticism was aimed at engine vibration and under-damped suspension, which allowed the fork to bottom out under heavy braking.
Notwithstanding the minor gripes, the Seca 650 sold well. Along the way, the Seca and its progeny earned a reputation for bulletproof reliability and durability, even surviving the indignities of turbocharging. (An XJ650 Turbo was even featured in the 1983 James Bond film Never Say Never Again.) The Turbo made a useful 90hp at 9,000rpm, and was one of the more reliable of the mid-size turbo bikes.
The Seca today
By the time the Eighties rolled around there were a surprising number of bulletproof engine designs out there, and the Seca’s mill was one of them. With regular maintenance, these engines live on longer than most people would expect. Though the lack of liquid-cooling will affect engine life in the end, it does add to the bike’s simplicity now (there’s no coolant to change!). And the shaft drive, with proper greasing, will last far longer than several chains and sets of sprockets, not to mention the lubing intervals are far longer.
With a small set of upgrades, these bikes are capable sport-tourers even today. Many people add braided-steel brake lines, Progressive fork springs, brake pads with more bite and tapered roller bearings in the steering head, and then they enjoy the heck out of them. The biggest struggle may be finding one for sale, because owners don’t seem to be quick to part with them, choosing instead to ride them.
Middleweight alternatives to the Yamaha XJ650 Seca
Suzuki GS650G Katana
– 65hp @ 9,400rpm (est.)/121mph
– Air-cooled, four-stroke, inline four-cylinder, double overhead cams
– Six-speed
– Twin-disc front, single rear
– 480lbs (dry)
– 50 MPG
– $1,500-$3,500
Suzuki first released the GS650G Katana in early 1981, which became the Mild Child of the Katana bunch when it’s bigger brother, the GS1000SZ Katana, came along in 1982. With its jet-fighter-esque bodywork and powerful air-cooled, inline four, the big Kat was a force to be reckoned with, and is remembered today as an important, direction-changing model for Suzuki. Still, its little brother may be the better motorcycle overall.
Offered for three years, the little Kat features a shaft drive, triple discs, real-world comfort and a bulletproof engine that makes it a very usable classic. The shaft drive means no chain to oil, and the Kat doesn’t exhibit the rise and fall effect common to many shaft-drive bikes. Many owners swear that if you ride the bike without looking, you wouldn’t realize it had a shaft at all.
The bike shown is a 1983 model, owned and phtographed by Richard Bruner. While the 1981 and 1982 models were similar, they lacked the small headlight fairing. While the appearance of the bike suggests a sporting riding position, a relatively low, 30.7in seat height means these bikes are surprisingly comfortable.
The smaller Kats are quickly becoming collectible. Look for a well-maintained example with a few more miles and save yourself some dough.
Kawasaki GPZ550
– 57hp @ 9,500rpm/119mph
– Air-cooled, four-stroke, inline four-cylinder, double overhead cams
– Six-speed
– Twin-disc front, single rear
– 469lb (wet)
– 55 MPG
– $800-$1,500
Introduced in 1981, the GPz was a hot-rodded version of the KZ550 street bike with an added air-charged fork, adjustable shocks and a bikini fairing. The press praised its handling on curvy roads and its comfy ergonomics for longer hauls. It was hailed as a bike that could be used as a commuter during the week and raced on weekends, not to mention one that would leave most 650s in its mirrors.
Though it obviously has a smaller engine than the Seca, its performance is more than a match for the bigger 650. The bike was produced from 1981 to 1985 (models from 1982-on sported Kawasaki’s single-shock Uni-Trak rear swingarm), so it’s more common than the 650 Seca, although it’s a little more focused on the sport end of the sport-touring continuum. That said, it’s not nearly as focused as many of the “race bikes-with-lights” sport bikes Japan Inc. turned out in the years that followed.
The GPz is definitely the easiest to find of the three bikes here, though examples aren’t quite as plentiful as they used to be. Still, decent, presentable, low-mileage bikes can be had for as little as $1,500 with rougher ones going for as little as $800. If you can’t find a Seca, this is your next best option.
