1988 Yamaha press information
TDR Features With the TDR, Yamaha create a totally new category in motorcycling. Powered by a two-stroke parallel-twin engine with YPVS and "cross-up" exhaust system, the TDR boosts instant acceleration far exceeding that of normal dual-purpose machines. The TDR is also the world's first two-stroke bike to use a CD ignition with digital advance system. Nimble handling and stunning acceleration for street use are combined with unmatched off-road capabilities, thanks to sturdy front forks, the rising-rate Monocross rear suspension, and front and rear disc brakes.1988 press kit Feature Map
TDR FEATURES
1) 2-stroke, 249 cc, liquid-cooled,
crankcase reed-valve, parallel twin-cylinder engine.
* Yamaha Power
Valve System (YPVS)
* Mikuni TM28SS flat-slide carburettors and fibre
reeds
* Low secondary reduction for increased traction
* Sealed,
continuous-link drive chain
* Sealed cooling system with alloy radiator
& coolant passage around exhaust ports
* Autolube oil injection
System with microcomputer-controlled oil pump
* Yamaha's "orthogonal"
engine mounting for reduced vibration
2) Capacitor discharge ignition
with microcomputer-controlled, digital timing advance System.
3)
"Cross-up" exhaust system featuring satellite -chromed silencers.
4)
Light' strong double-cradle frame fabricated of high-tensile steel tubes.
Tapered roller bearings are used at the steering head.
5) Sturdy 38 mm
front fork is adjustable for air pressure and spring pre-load. Provides
160 mm of wheel travel.
6) Rising-rate Monocross rear suspension uses a
De Carbon-type gas/oil damper and a box-section, high-tensile steel
swinging arm. Rear wheel travel is 150 mm.
7) A drilled, 320 mm front
disc stopped by a 4-pot, opposed-piston calliper. The rotor is floating for
precise control.
8) The rear brake consists of a drilled, 210 mm disc
and an opposed-piston calliper.
9) Stylish head fairing is mounted to
the petrol tank for nimble handling. lt houses a powerful 60/55W halogen
headlamp.
10) Simplified instrument panel features tank-- mounted
tachometer for easy reading.
11) The tank holds 14 litres of petrol and
uses an aircraft-style filler cap and a negative pressure activated
tap.
12) Roomy' deeply padded seat is 820 mm from the ground. Separate
passenger grab bars are fitted to the tail cowl. The oil tank, air filter,
tool and glove boxes are situated beneath the seat.
13) 18" front and
17" rear spoked wheels have aluminium rims, and are shod with Metzeler or
Bridgestone high-grip tyres. Low front fender helps cooling
efficiency.
14) Lightweight cast-aluminium pillion footrest
brackets.
SPECIFICATION TDR 250
ENGINE*[ ] = French model
Type 2-stroke, liquid-cooled, crankcase reed-valve, parallel
twin-cylinder
Displacement 249 cc [239 cc]
Bore and stroke 56.4 x 50.0 mm [55.2 x 50.0 mm]
Compression ratio 5.9:1 [5.7:11
Maximum power (DIN) 50.3 PS (37.1 kW) @l0,000 rpm
[44.3 Ps (32.6 kW) @10,000 rpm]
Maximum torque (DIN) 3.7 kg-m (36.2 Nm) @8,500 rpm
[3.5 kg-m (34.6 Nm) @9,500 rpm]
Carburetion Mikuni TM28SS x 2
Ignition Capacitor discharge, with digital timing advance
Starting Kick
Lubrication Autolube oil injection
Oil tank capacity 1 .4 litresTransmission
Type 6-speed, constant-mesh
Primary reduction ratio .... 5 6/22 (2.545)
Secondary reduction ratio . . 45/14 (3.214)
Gear ratio, 1st 36/14 (2.571)
Gearratio,2nd 28/16 (1.750)
Gearratio,3rd 25/19 (1.316)
Gearratio,4th 26/24(1.083)
Gear ratio, 5th 25/26 (0.962)
Gear ratio, 6th 23/27 (0.852)
Clutch type Wet, multi-plate
Final drive ChainCHASSIS
Overall length 2,145 mm
Overall width 785 mm
Overall height 1,2 15 mm
Wheelbase 1,385 mm
Minimum ground clearance 230 mm
/span>CHASSIS
Overall length 2,145 mm
Overall width 785 mm
Overall height 1,2 15 mm
Wheelbase 1,385 mm
Minimum ground clearance 230 mm
Seat height 820 mm
Dry weight 137 kg
Fuel tank capacity 14.0 litresSuspension
Front Telescopic fork (160 mm travel)
Rear Rising-rate Monocross (150 mm travel)Brakes
Front Hydraulic disc, with 320 mm floating disc and 4-pot opposed-piston calliper
Rear Hydraulic disc, with 210 mm disc and opposed-piston calliperTyres
Front 100/90-18H
Rear 120/80-17H