Road test: 2004 Yamaha Road Star

The road to wellness begins with boring out the world’s largest production air-cooled pushrod V-Twin 2mm, taking it from 1602cc to 1670cc. The forged pistons that fill the better-sealing, increased-durability ceramic-composite cylinders are now 97mm - that’s almost 4 inches across, more like the pistons for a P-51 Mustang. New rocker arms have been shortened to reduce inertia and increase rpm, and additional fin area has been added to keep the motor cool. The lift of the camshaft has been radically changed to keep the eight valves opened longer for more power.