Yamaha TDR 250

Yamaha TDR250
Manufacturer	Yamaha Motor Company
Also called	Ultimate Dual
Production	1988 – 1993
Class	Dual Sport
Engine	249cc two-Stroke parallel twin YPVS
Transmission	6-speed constant mesh manual, chain final drive
Wheelbase	1,385 mm (54.5 in)
Dimensions	L: 2,145 mm (84.4 in); W: 785 mm (30.9 in)
Seat height	820 mm (32.3 in)
Weight	137 kg (302 lb) (dry)
Fuel capacity	14.0 L (4 US gal; 3 imp gal)
Related	Yamaha R1-Z, Yamaha TZR250

The Yamaha TDR250 was a street-legal middleweight dual-sport bike produced by Japanese motorcycle manufacturer Yamaha between 1988 and 1993.

It was powered by the naturally-aspirated, crankcase reed-valve inducted, liquid-cooled 249cc parallel-twin two-stroke engine from the first generation TZR250 (this same engine also powered the R1-Z). This engine featured the ‘YPVS’ Yamaha Power Valve System, CDI ignition and digital spark advance [1]. Almost all of the engine, gearbox, and electrical components are interchangeable with the TZR and R1-Z.

The TDR was designed to provide agile handling and quick acceleration both on and off the road, and power delivery was modified to suit its intended use [2]. The special upswept expansion chambers, unique to the TDR, part of this; as well as aiding ground clearance. The bike was originally released in a 250cc format, but a 240cc derivative was also produced exclusively for the French market.

Specifications of TDR 250

Specifications for 1988 – 1993 model [3]
Engine Type	Parallel Twin Cylinder, Water Cooled, Two-Stroke, YPVS
Carburetion	Mikuni TM28SS x 2
Displacement	249 cc [239 cc]
Bore × Stroke	56.4 x 50.0 mm [55.2 x 50.0 mm]
Peak Power	50.3 PS (37.1 kW) @ 10,000 rpm [44.3 PS (32.6 kW) @ 10,000 rpm]
Peak Torque	3.7 kg-m (36.2 Nm) @8,500 rpm [3.5 kg-m (34.6 Nm) @9,500 rpm]
Compression Ratio	5.9:1 [5.7:11]
Fuel Capacity	14.0 L (4 US gal; 3 imp gal)
Oil Capacity	1.4 L (0.4 US gal; 0.3 imp gal)
Seat Height	820 mm (32.3 in)
Dry Weight	137 kg (302 lb)
Tires	Front 100/90-18H Rear 120/80-17H
Brakes	Front Hydraulic disc, with 320 mm (12.6 in) floating disc and 4-pot opposed-piston caliper. Rear Hydraulic disc, with 210 mm (8.3 in) disc and opposed-piston caliper
Final drive	Chain