THE STORY

The Yamaha XS 1100 engine design was in reality a completely new design with several relatively unconventional elements when compared to other inline 4-cylinder motorcycle engines of the day.

The engine does not transmit power directly from the crankshaft to the clutch basket/input shaft, but instead via a wide hy-vo chain onto an intermediate jack-shaft with a cush-drive damper.  The engine rotation was clockwise when viewed from the left side and not counterclockwise as all other inline 4-cylinder motorcycle engines of the day.

The engine is mounted in rubber bushing making it almost completely vibration-free when running.

A significant advancement of the XS 1100 engine are the combustion chambers.  The design allows for high compression without large piston domes and large ignition advance.

In the lead up to the 1979 Castrol Six-Hour, the XS 1100 won the Adelaide Three-Hour, the Perth Four-Hour and the Surfers Three-Hour.  The unlikely XS 1100 and Pitman Yamaha rider Greg Pretty had upstaged the biggest and baddest production bikes around.

THE BIKE

This Yamaha XS 1100 is mostly original with some custom paint detailing.