A shift drum is a cylindrical shaped transmission component with machined slots around its outside diameter. When actuated by the external shift mechanism it moves the the internal shift forks. As the shift drum is rotated, drum slots cause the shift forks to move sliding gears or dogs, causing the engagement and disengagement of various [...]

Many touring motorcycles, cruiser style motorcycles and ATVs utilize a shaft drive as their final drive. A shaft drive system consists of a drive shaft, universal joints and gears to connect the transmission output shaft to the rear wheel. Shaft drive is a very low maintenance type of final drive, but it’s heavy and cannot [...]

We’ve all seen him before – he’s the idiot riding that bike down the highway with flip-flops on his feet, his T-shirt riding up his back, flipping around with the wind. He MAY have a pair of gloves on but don’t count on it. He’s most likely got a decent helmet but you’ll often find [...]

The slide cutaway refers to the carburetor circuit which controls the air/fuel ratio from one-eighth to one-quarter throttle opening on slide type carburetors. The height of the cutaway portion of the carburetor slide controls how much air is mixed with fuel, the larger the slide cutaway number the leaner the transition off of idle will [...]

The theoretical optimum ratio of air to fuel of 14.7 :1 by weight.