It appears you're interested in specifications for the NSU 351 OSL. This Sport model is powered by a Single cylinder, four-stroke engine with 346.00 ccm (21.11 cubic inches) of actual displacement before compression. Fueling is metered via Carburettor. Graetzin KE 25/43 allowing this machine to produce its 18.00 HP (13.1 kW) horsepower and torque. According to our records engine heat of the NSU 351 OSL is moderated by Air. You'll need to get familiar with the 4-speed transmission and pay attention to final drive Chain maintainence. Our best information shows that the front tire size is 3.25-19 and the rear is 3.25-19 . The entire package is supported by the frame, Open double steel. 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) rear brakes. The NSU 351 OSL was launched in 1940, 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.