Little Brother: 1976 Kawasaki Z2 750

The size of the Z2 engine was mandated by Japanese government regulations in the 1970s, which set a maximum displacement for motorcycles of 750cc. In fact, 750cc was the original displacement of Kawasaki’s prototype Four, which was almost ready for public display in 1969 when Honda announced its market-shattering CB750. The upstage was a setback for Kawasaki, which wanted to triumph over rival Honda, not merely match it, so Kawasaki’s engineers went back to the drawing boards. The result, appearing in 1972, was the Z1, a 903cc double overhead cam monster that, in addition to horsepower and speed, offered decent handling, reasonable gas mileage and reliability.

With the rest of the world duly impressed, Kawasaki embarked on a redesign of the Z1 for the home market, spearheaded by chief engineer Ben Inamura. Instead of simply sleeving down a 900, Inamura and his team decided to work out the best configuration for a smaller machine. As a result, the development work on a 750cc model took an additional six months, even though most of the cycle parts were intended to be the same as the ones on the Z1.

In December 1972, Kawasaki called a press conference at the Takanawa Prince Hotel to announce the Z2 (sometimes referred to by the factory as the 750RS) to its Japanese dealers. The new Z2 had a 64mm bore x 58mm stroke (versus the Z1’s 66mm x 66mm), a redesigned crankshaft, and smaller, 26mm carburetors for an output of 69 horsepower at 9,000rpm. The rear sprocket had 42 teeth instead of the 35-tooth Z1 item, but aside from the sprocket, most of the cycle parts were the same as the Z1, although matched to Japanese government regulations — including beeping turn signals and a red light in the center of the headlight that went on at speeds over 80mph to shame the rider into throttling down. Actual retail sales started in March 1973. Most motorcycles sold in Japan were and still are smaller displacement than bikes sold in the U.S., and the Z2 shone in the limited Japanese big-bike market, with sales 10 percent higher than the nearest competitor. Its popularity was such that it was featured in a Japanese anime series.

Z2 changes

Compared to the Z1, which was sold in large numbers all over the world, the Z2 was a low-production model, with about 3,600 built in 1973, the first year of production. The bike went through several model year changes, often matched to changes made to the Z1, but the Z2 kept the black engine paint that appeared on the original version of the engine, in contrast to the Z1, which fairly early on went to a natural aluminum finish. The Z2 also always had a 4-into-4 exhaust system, while the Z1 went to a 4-into-2 system.

The 1976 version of the 750 was known by the additional model designation A4. It was available in either Diamond Brown or Dark Green, and went on sale in March of that year. The A4 had twin disc brakes in front and a drum brake in the rear, a European-style saddle with a strap, and short, U.S.-style fenders. The engine internals didn’t change from previous versions, but although max horsepower was now 70 horsepower, somehow the bike had become 10 kilometers per hour slower, with a top speed of 190kph (a little over 118mph). Also, the regulation red warning light was moved to a bracket on the handlebars.

The production run for the 750-A4 was quite short — only about six months, with only an estimated 1,980 made before the A4 was replaced by the very similar A5 model for 1977. Production of the Z2 ended in 1978, when the bike was replaced by the Z750FX. A version of the Z2 was built for the South African market in the late 1970s.

Z2 collectors

Andreas Strieve is a collector of big-bore Japanese motorcycles from the Seventies and Eighties — the kinds of bikes your mother was sure you would kill yourself on, but that impressed all your friends at the burger stand. And unlike many collectible motorcycles, you can still take these bikes out on the highway and do a little careful canyon carving with them. Once restored, these machines usually only need frequent oil changes and a trickle charger on the battery to stay in good condition, ready for another run down the road. Andreas likes to ride as well as work on bikes, and his Seventies bruisers are a good fit for his interests.

The story of this particular Z2 starts with Andreas’ friend Trace St. Germaine, a drag racer and builder of drag racing engines. Trace had a buddy who was stationed in Japan in 1976, and returned from his stint with the armed forces with the A4 version of the Z2. After parking it for many years in his garage, Trace’s buddy finally decided to part with his Z2 and sold it to Trace and Andreas, who decided to own and restore it together.

As bought, the Z2 was in one piece, but painted black, with a chain and sprocket from a Z1 and aftermarket pipes. It hadn’t run for a while, the carburetors were gummy and the fluids needed changing. Andreas points out that, although this is a rare model, most of the cycle parts are the same as those on the much more common Z1. In fact, if you look carefully at the new-old-stock mufflers, they have “Z1/Z2” stamped on them.

Trace did most of the engine work, including changing all the fluids and freeing a stuck valve. Trace and Andreas carefully cleaned the carburetors and Trace changed the jets. New-old-stock exhaust pipes and mufflers were easy to locate, since that year’s Z1 used the same exhaust system, and the correct counter sprocket and chain are available from Japanese websites. The one missing item was the emergency flasher. The bracket is there, but the switch is not, and a correct replacement costs an arm and a leg. Trace and Andreas are currently looking for a cost-effective alternative. With the running gear repaired, the owners moved on to the cosmetics. Trace and Andreas touched up the paint on the frame and engine, repaired the tank and the side covers and sent the tank out to be painted by the expert hand of Brian Jennings at Bay Automotive in Concord, California. Trace has a factory-paint Z1 from the same year as this Z2, and as both bikes used the same color scheme, matching the paint was easy. With the paint finished and all the shiny parts polished, the pair was finally ready for the fun part — taking the Z2 out on the road.

Road ready

By the time this Z2 was manufactured, Kawasaki had become confident enough in its electrical system to dispense with a
kickstarter. “It’s warm blooded,” Andreas says. “You pull the clutch in, put the choke on, give it a little gas and hit the button. It starts right up and idles nicely. Now that we have the proper sprockets, it has wonderful power. It’s not quite as powerful as the Z1, but it is very smooth.

“The Z2 has a very nice even power curve,” Andreas continues. “It starts really pulling at 6,000rpm, and pulls nicely from there to redline at 9,000rpm. We rebuilt the dual discs, but used the stock suspension. We tried to keep the bike as stock as possible. We had to replace one of the carburetors, but since Kawasaki used the same Mikunis on one of their 2-strokes that was imported here, we were able to find a NOS replacement. The carbs work just fine.”

Andreas has ridden the bike enough to decide that he likes it, but hasn’t really tested the Z2 out on a mountain road since the rebuild. “I haven’t really gone canyon carving on this bike yet. So far, it is solid in turns, but it is not a light bike and probably likes big sweepers better than really tight twisties,” Andreas says, although he says it has proven great for general, around-town riding. “It’s got good midrange and an upright riding position. The seat is very comfortable, and there is enough room for two slim people. You have to remember that it was built for the Japanese market, and the average rider there is much slimmer than the average American.” Andreas also has a Z1 and feels that the bike is similar, but has its own charm. “The Z2 is a mini Z1. It has a little less power, but it’s smoother than a Z1, just a touch smoother.”

The maintenance is similar to that on a Z1, and most parts for the 750 are the same as a Z1 for the same year and are easily available — one of the few exceptions being the final rear sprocket. Once properly set up, the carburetors tend to stay tuned, although the points need to be checked every once in a while if the bike still has the original ignition. Many owners turn to one of the several easily available electronic ignitions.

The major difference in maintenance between the Z2 and a modern machine is the need for more frequent oil changes. You should change the oil at least every 2,000 miles — more often if the bike sits for an extended time. With the exception of the oil changes — and the fact that unless you can read Japanese, the stickers aren’t comprehensible — the Z2 is a perfectly good, all-around motorcycle. “It’s pleasurable to ride,” Andreas says.

The rarity of the Z2 in the U.S. has turned the bike into a collector’s item, a reality that would drive many people to put it on display in a museum. New Z2 owners Andreas and Trace think that would be really unfair to a good motorcycle that deserves to be out on the road. MC