It appears you're interested in specifications for the Yamaha MR50. This Enduro / offroad model is powered by a Single cylinder, two-stroke engine with 49.00 ccm (2.99 cubic inches) of actual displacement before 6.0:1 compression. Fueling is metered via Carburettor. VM16SH carburetor allowing this machine to produce its horsepower and torque. According to our records engine heat of the Yamaha MR50 is moderated by Air. 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 2.50-18-4PR and the rear is 3.00-16-4PR . The entire package is supported by the frame, Semi-double cradle, steel tubular. We know you like to go fast or cruise all day, but when you need to stop, you'll be dependant on Expanding brake (drum brake). Mechanical drum brake Leading - Trailing front brakes and Expanding brake (drum brake). Mechanical drum brake Leading - Trailing rear brakes. The Yamaha MR50 was launched in 1980, 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.