It appears you're interested in specifications for the Yamaha TT-R 90. This Cross / motocross model is powered by a Single cylinder, four-stroke engine with 89.00 ccm (5.43 cubic inches) of actual displacement before 8.5:1 compression. Fueling is metered via allowing this machine to produce its 5.60 HP (4.1 kW) horsepower and 6.10 Nm (0.6 kgf-m or 4.5 ft.lbs) torque. According to our records engine heat of the Yamaha TT-R 90 is moderated by Liquid. You'll need to get familiar with the transmission and pay attention to final drive maintainence. Our best information shows that the front tire size is and the rear is . The entire package is supported by the frame, . We know you like to go fast or cruise all day, but when you need to stop, you'll be dependant on Expanding brake front brakes and Expanding brake rear brakes. The Yamaha TT-R 90 was launched in 2002, and we're happy to know (or assume) you've got one in your garage. To help you keep your ride in tip-top shape, consider purchasing an owner or service manual.