Honda Gold Wing
No such list is complete without including the Honda Gold Wing, perhaps the best known six-cylinder motorcycle. Though it began life with a flat-four, the 1987 embiggening of its fourth generation saw two more cylinders added, resulting in a 1500cc flat-six, like a Porsche. A six-cylinder engine has remained a staple of the 'Wing ever since, now enlarged to 1800cc.
Its flat engine configuration is a perfect fit for full size touring bike. All of the engine weight sits low in the frame, which makes the Gold Wing a surprisingly good handling bike for its size. I watched a recent model silently glide by me at over 100 mph on the track, then scrape its footpeg leaning into the next turn after barely slowing down. No Harley Electra-Glide could do that.
We must also give an honorable mention to the Honda Valkyrie. Though technically a separate model, it's essentially a Gold Wing in cruiser clothing. I almost bought an older one once, but the prospect of cleaning and synchronizing six carburetors scared me away.
BMW K 1600
BMW built a reputation on moderate displacement six-cylinder engines in most of their cars during the 1980s and 1990s. That's changed in recent years as displacements have decreased for efficiency, but to a certain extent, that legacy lives on in the K 1600.
Unlike the flat-six in the Gold Wing, the K 1600 puts all of its cylinders in a row, angled forward at 55 degrees to try and keep the weight low like the Honda. At only 22 inches wide, BMW claims this is the narrowest inline six-cylinder engine ever made, and I believe them. Does it work? Some prefer the Beemer, while others prefer the 'Wing. With that kind of split, it really comes down to personal preference, so I'd say that BMW has succeeded.
The motorcycle most people think of when it comes to six-cylinders is the Honda CBX. Unlike the BMW's relatively narrow engine, the CBX's powerplant overhangs the frame on either side. It looks massive, especially with six pipes bending out and around the block, but in reality, it's only two inches wider than the CB750's powerplant.
Although this was the first six-cylinder production bike Honda ever made, its roots lie in the RC racer of the 1960s. Honda originally built the CBX as a sportbike. When introduced in 1978, motorcycles didn't need sleek bodywork to be superbikes, which still followed the naked path blazed by the CB750. This changed in 1981 when the faired CBX-B became a sport-touring bike, perhaps foretelling the direction Honda would later take the Gold Wing.
Not to be outdone, Kawasaki released their own six-cylinder bike just one year after the CBX, called the Z1300. It may look like a copy of the CBX with a square headlight, but that's far from the truth. As its name suggests, the Z1300 had a 1300cc displacement, bigger than the CBX's 1000cc. It was also water-cooled while the CBX relied on good old fashioned air, and shaft drive where the CBX used a chain. On paper, it looks like a better motorcycle.
For whatever reason, though, they were not as popular as the Honda. Kawasaki, too, turned it into a touring bike, with the addition of a windshield, luggage, and a redesigned frame to handle the extra weight. In Europe, Kawasaki called it the Voyager, the first time they used the name that would come to define their touring bikes. It had a longer life than the CBX, lasting until 1989 while the CBX died in 1982. The Voyager name still lives on today in the Vulcan 1700 Voyager.
Benelli 750 Sei
Many people believe that the Honda CBX was the first six-cylinder motorcycle, but that is not the case. That honor goes to the Italians with the Benelli 750 Sei. Introduced in 1972, it was built in small numbers through 1978, the same year the CBX came out. The Benelli's engine was increased from 750 to 900cc for 1979 through 1989.
The confusion with a Honda is justified, however, when you look at the engine. It's strongly based on the CB500, just with two extra cylinders added to bring the displacement up to 750cc. Rather than the Honda's four carburetors, the Sei's six cylinders shared three Dell'Orto VHB 24mm carbs. The alternator moved behind the engine from Honda's position on the left side of the crankshaft. It makes me wonder if Honda actually got the idea for the CBX from Benelli.