The hottest moto-market right now isn’t flagship superbikes and adventure bikes, as much as motorcycle keeners would like to believe that. It’s true that flagship models are faster and safer than ever before, with tech that would have seemed sci-fi only a generation ago. But, what do you think Kawasaki sells more of when you factor in total global sales: The Kawasaki ZX-10R, or the Ninja 400?
With developing markets slowly acquiring more buying power, and developed markets slowly losing their buying power, motorcyclists from both ends of the spectrum are meeting in the middle, buying bikes with sporty styling, but practical small-cc engines and affordable pricing. Again, the Ninja 400 is a great example here, as well as the ZX-25R in overseas markets. And you’d certainly expect Kawasaki to do well in this market; Team Green basically owned the segment for years with the Ninja 250, and really, its GPZ305 was a key model in entry-level sportbike evolutionary history.
In the 1980s, the GPZ name stood for something. The Eddie Lawson GPZ1100 ELR was an iconic machine at the start of the decade, celebrating Eddie Lawson’s AMA Superbike success with Kawasaki. Later on, Tom Cruise kept the hype alive by flogging the GPZ900 Ninja along through Top Gun, en route to hot dates with Kelly McGillis. Who wouldn’t want a GPZ, with the promise of racing championships, military-industrial complex glory, and a bombshell girlfriend to boot? Other motorcycles might have been superior in many ways, but you didn’t see their riders landing romance with movie actresses and shooting down MIGs.
Not everyone’s budget could spring for the big-bore GPZ, though, or even the middleweights in the line. To appeal to riders with superbike dreams and empty wallets, Kawasaki brought out the GPZ305 in 1983.
Or at least, that seems to be the general consensus online—Wikipedia and other highly reliable sources compiled by large-brained experts all say GPZ305 production ran through 1983 and 1984, and then ended. Except, the bike listed for sale here is a 1987 model, and I’m fairly certain I remember some ’86 models around town when I was a kid. The truth is, when you get to Japanese motorcycle production in the 1980s, it’s often hard to know the truth. Sometimes a model could be canceled in one market, and continue sales in other markets for many years. But then, maybe all those bikes were just leftovers, advertised as later-production machines than they actually were? That sort of thing has been known to happen, too.
Suffice it to say, the GPZ305 was built through the mid-’80s, with styling appropriate to the era. It looked like a mid-’80s superbike, sort of, if you stood back and squinted. It came with a bikini fairing and other sporty accoutrements.
The engine, though, was definitely not sporty. It was an air-cooled 306 cc four-stroke parallel twin, making roughly 27 horsepower at 10,000 rpm, and 19 pound-feet of torque at 8,500 rpm (depending who you ask). Not bad, really, sounds like the sort of bike that would be a fun backroads flog, if it wasn’t for the cheap chassis … and the fact that the engines had a rep for terrible, terrible reliability.
The GPZ305 had one especially major weakness: A plastic gear in the oil pump, which had a reputation for stripping out its teeth. Once that happened, the 305 engine lost its top end oil pressure, and shortly afterwards, its top end.
A former boss of mine actually had one of these bikes, and said he caught the problem just in time, before his bike grenaded during a weekend trip. Back then, I believe there was some sort of aftermarket fix or DIY bodge that solved the issue; I’m not sure how you’d fix it now.
There were other weaknesses, too. The camshaft was a cheap, shoddy design, and there were other weak points in the oiling system. One major weak point in the oiling system is bad enough, but multiple points of failure? Yikes.
Better than you’d think
And yet, while many owners had terrible experiences with their small sportbikes, other GPZ305 riders found these were lots of fun if well-maintained. Thanks to the six-speed gearbox, you could reach a theoretical speed of just over 100 mph. There was a belt drive instead of chain drive, which kept driveline maintenance to a minimum. The 305 engine had excellent fuel economy, and with a wet weight just over 350 pounds, the machine was much lighter than the big-bore four-cylinders of the day. Dual disc brakes came standard on many models (not on this bike pictured, though), a novel innovation for a 1980s budget bike. And again, the styling, although very dated today (look at those skinny bicycle tires on 18-inch rims!) was spot-on for the era. The suspension was sort of lightweight, but it was adjustable, which is more than you can say about some entry-level sportbikes today.
As I said, my former boss Rob Harris owned one, and despite its poorly-designed engine, he toured all over Scotland on his GPZ when he was young. As for myself, I never owned one, but came very close to buying a 305 a couple of times when I was a kid. These bikes were everywhere gathering dust in barns and garages when I was growing up in rural Prince Edward Island. With a speed limit that topped out at 90 km/h, the little twin was perfect for the area. I clearly remember looking at buying one for $600 when I was in my early 20s; it was in mint shape, except for a small dent in the tank and a broken turn signal from a stop sign tipover.
Did I miss out on a great deal, or did I cleverly avoid buying a bike with a time bomb engine? Hard to say, but if I just bought the machine and stored it carefully, that mint-condition finish would have paid me back, if I kept it in good nick. This machine for sale in Hamilton, Ontario, Canada, is listed at $2,500, and I wouldn’t be surprised if the seller gets it. Small-cc bikes are selling very well these days, thanks to supply chain issues restricting dealership supply. With a history reaching back almost 40 years, these bikes are also becoming collectible in their own right, especially considering their heritage.
See, these machines aren’t just a cool oddball from the ’80s. The GPZ305 is also the forerunner of a machine that really did change the motorcycling world. After Kawi canned the 305, it brought out the EX250 Ninja. Here, it fixed the mistakes it made with the GPZ; the engine was a reliable liquid-cooled twin, and until 2012, this basically ruled the entry-level 250 sportbike market.
Honda blew that market wide open with the CBR250, a machine which had implications on the global motorcycling scene that probably aren’t even fully realized today. Now, we have the CBR300, CBR500, Ninja 400, R3, RC390, and many other machines in this entry-level class. All those bikes owe at least some thanks to the EX250 Ninja, and that bike owes lots of thanks to the GPZ305, which paved the way for small-cc sportbikes.
As said above, this machine is for sale in Hamilton, Ontario. The coronavirus pandemic would mean out-of-town shoppers would find it difficult to acquire the bike, but not impossible. If you’re interested, send the seller a message; these bikes are rare in North America, and especially in the US, where they had a very short run in salesrooms. You might want to check out the oiling system before firing it up, though …