The problems develop when a worn bushing on the starter clutch causes the gears to slip out of mesh in the beginning of a kick, and your leg slams straight and tries to bend the knee in the wrong direction. It's called "Sportster knee".
What other Harley, or motorcycle for that matter, has crippled more people than the legendary Sportster kickstart? If rebounding compression wasn’t dislocating the knee or throwing the rider over the handlebars then the slip-through kick start gears extend the leg past where its supposed to go .snapping the kneecap. Sportster knee, the tell tale limp, familiar with riders of the era is a badge of honor. The electric start has saved a whole generation from this mind numbing pain. This "half-a-Harley" with a short man complex is meaner than a junk yard dog?