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Yamaha TZR 250R
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Make Model |
Yamaha TZR 250R (3XV) |
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Year |
1992-93 |
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Engine |
Liquid cooled, two stroke, 90° V-Twin
cylinder, read valve induction |
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Capacity |
249.7 |
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Bore x Stroke |
56 x 50.7 mm |
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Compression Ratio |
7.5:1 |
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Induction |
2x Mikuni flatside carbs |
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Ignition /
Starting |
Microcomputer controlled / kick |
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Max Power |
45 hp @ 9500 rpm |
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Max Torque |
3.8 kg-m @ 8000 rpm |
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Transmission /
Drive |
6 Speed / chain |
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Front Suspension |
39mm Upside-down forks |
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Rear Suspension |
Monocross linkage |
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Front Brakes |
2X disc 4 piston calipers |
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Rear Brakes |
Single disc 2 piston caliper |
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Front Tyre |
110/70 Z17 |
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Rear Tyre |
150/60 Z17 |
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Seat Height |
780 mm |
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Dry-Weight |
126 kg |
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Fuel Capacity |
16.5 Litres |
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Top Speed |
112 mpg 180.2 km/h |
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Review |
bbb-bike.com |
Visually, the TZR is a spitting image of John
Kocinski's 1990 world-championship-winning works Yamaha YZR250, save for its
lights, turnsignals, passenger perch and lack of sponsorship decals. In actual
ancestry, the TZR is a close relative of Yamaha's TZ250D production racer, the
two sharing the same crankcases, bore and stroke, displacement and 12,000-rpm
redline.
As on the TZ, the TZR is powered by a
counterbalanced, two-stroke V-Twin with a bore and stroke of 56.0 x 50.7mm for
a displacement of 249cc. TZ-style reed valves and a six-speed, cassette-type
transmission add to the list of road-race-quality components.
Bloom provided us with a 1991 TZR to sample at
Laguna Seca Raceway. Unfortunately, the only one he had available at the time
was a Japanese-spec model limited by that country's strict home-market
regulations to a claimed 45 horsepower-about one-third less than on
non-restricted versions. But despite its reduced power output, it still
impressed us with its overall performance.
For one thing, the engine possesses a
surprisingly wide powerband, attributable to its computer-controlled
engine-management system. An eight-bit microcomputer controls the advance
curve of the electronic ignition, the actuation of the exhaust pow-ervalve,
and the fuel mixture provided by the flat-slide 26mm Mikunis.
All of this allows the little 250 to pull
cleanly and steadily from low rpm,
but the real but the real
excitement is found on the upper floors of the rpm scale. Kept zinging
between 8000 and 11,000 rpm, the engine is surprisingly potent and exciting,
even if it does fall far short of the championship-caliber performance of the
YZR250 roadracer, which pumps out nearly twice the power of the TZR. Though
unable to measure top speed, we saw an indicated 155 kph (about 96 mph) over the
crest of Laguna's Turn One. But those who lust after 250 race replicas don't
expect Superbike-level engine performance. They place greater value on
lightning-quick handling, which is the TZR's greatest virtue. The bike's
aluminum, twin-beam Deltabox frame, allied with ultra-responsive steering
geometry (24 degrees of rake, 3.5 inches of trail) and a 278-pound claimed dry
weight, allowed the TZR to be flicked through Laguna's infamous Corkscrew with
almost ridiculous ease. But that agility also has its drawbacks, as the TZR's
responsive nature requires an equally light touch at the controls. Ham-fisted
riders need not apply.
Braking is outstanding. The TZR's 39mm inverted fork is fitted with
four-piston calipers pinching a pair of floating discs. Even under repeated
abuse around Laguna's 11-turn circuit, the brakes consistently provided
excellent feel and were resistant to fade.
Though our riding time on the Yamaha was limited, both fellow
Associate Editor Don Canet and 1 came away with a strong appreciation for the
TZR's phenomenal handling. No, the TZR250R will not break any speed records or
set blazing quarter-mile times; but when it comes down to consuming corners,
nothing currently in any manufacturer's U.S. lineup even comes close.
Matthew Miles 1992
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