Retro Muscle: Motocrew’s GPZ900R is the business

There’s a lot to be said for a good old-fashioned muscle bike. And in the 1980s, the Kawasaki GPZ900R was the benchmark. It didn’t have any of the nanny state electronics we’re used to today, but the raucous, liquid-cooled DOHC four punched out 113 solid horses—and propelled the GPZ to 150 mph or more. No wonder the producers of the original Top Gun movie selected a GPZ to star alongside Tom Cruise, who knows how to handle a bike. We’ve noticed an uptick in custom GPZs lately, going right back to ICON’s ‘Old Ghost’ of six years ago. AC Sanctuary...