It appears you're interested in specifications for the Excelsior JAP Speedway. This Speedway model is powered by a Single cylinder, two-stroke engine with 497.00 ccm (30.33 cubic inches) of actual displacement before compression. Fueling is metered via Carburettor. Amal 27/013 dual-float allowing this machine to produce its horsepower and torque. According to our records engine heat of the Excelsior JAP Speedway is moderated by . 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 (drum brake) front brakes and Expanding brake (drum brake). Dunlop alloy-rim rear brakes. The Excelsior JAP Speedway was launched in 1949, 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.