The answer lies partly in the technology, partly in the marketing and partly in the timidity of the manufacturers.
Expectations were high when rumors swirled in the early ‘80s that motorcycles with turbochargers would soon be available. Evidence from the car world suggested these would be giant-killers, with acceleration to make you scared.
At the time, engine development was well ahead of chassis technology and hwat the really powerful motorcycles needed most wasn’t more horsepower but a way of getting the power to the ground. Had turbocharging been patient enough for perimeter-alloy chassis technology to emerge, history may have written differently.
Instead, the 90 horsepower Yamaha XJ650T, the 82 horsepower Honda CX500T, the 85 horsepower Suzuki XN85 and, finally, the 112 horsepower Kawasaki GPz750T were all sold between 1982 and 1988, with some models only being available for two years.
Here’s what they were like to ride. If you dialed up the revs from a standing start, no sense of turbocharging was felt. Naturally aspired siblings would get away because they were lighter, but you’d reel them in eventually. In tight conditions, turbo lag meant you didn’t have grunt out of corners and, when it made itself felt, you were about to enter the next corner when you didn’t need it. They were hard motorcycles to ride quickly on twisty roads.
The one sensation worth paying for was the feeling of rolling on the throttle in a high gear. It was like you were being fired out of a sling-shot. No naturally aspirated motorcycle can equal it.
The best of the four was the Kawasaki GPz750T, but it was almost immediately eclipsed by the legendary Kawasaki GPz900, which was cheaper and faster.
The mistake with all of them was turbocharging smaller engines. Yes, the frames of the bigger motorcycles wouldn’t have handled the power, but it was tough for the marketing departments to sell an expensive motorcycle that was slower in most conditions than the motorcycle on which they were based.
Turbocharged motorcycles were killed in the ‘80s. Arguably forever. But currently motorcycle manufacturers are looking at turbochargers again as a source of extra power and better and more efficient ways to burn fuel...