The hottest motorcycle market right now is not flagship super motorcycles and adventure motorcycles as much as motorcycle enthusiasts would like to believe. It’s true that the flagship models are faster and safer than ever, with technology that would have seemed like science fiction just a generation ago. But what do you think Kawasaki sells the most when you factor in total worldwide sales: the Kawasaki ZX-10R or the Ninja 400?
As developing markets slowly gain more purchasing power and developed markets slowly lose purchasing power, motorcyclists on both ends of the spectrum meet in the middle, buying sporty-style bikes, but practical engines. small displacement and affordable prices. Again, the Ninja 400 is a prime example here, as well as the ZX-25R in overseas markets. And you would certainly expect Kawasaki to do well in this market; Team Green essentially owned the segment for years with the Ninja 250, and truly, their GPZ305 was a key model in the history of entry-level sportbike evolution.
Taming the Twin
In the 1980s the name GPZ stood for something. The Eddie Lawson GPZ1100 ELR was an iconic machine from the start of the decade, celebrating Eddie Lawson’s AMA Superbike success with Kawasaki. Tom Cruise later fueled the hype by whipping the GPZ900 Ninja alongside Top Gun, en route to hot dates with Kelly McGillis. who would not Want a GPZ, with the promise of racing championships, the glory of the military industrial complex, and a bombshell girlfriend to boot? Other motorcycles could have been superior in many ways, but you haven’t seen their motorcyclists land a romantic relationship with movie actresses and take down MIGs.
However, not everyone’s budget could come out for the full-bore GPZ, or even the middleweights of the line. To appeal to riders with superbike dreams and empty wallets, Kawasaki released the GPZ305 in 1983.
Or at least, that seems to be the general consensus online – Wikipedia and other highly reliable sources compiled by broad-minded experts all say that the production of GPZ305 took place in 1983 and 1984 and then went on. finished. Except, the bike on sale here is a 1987 model, and I’m pretty sure I remember some 86 models in town when I was a kid. The truth is, when you get to the production of Japanese motorcycles in the 1980s, it is often difficult to know the truth. Sometimes a model can be canceled in one market and continue to sell in other markets for many years. But then, maybe all of those bikes were just leftovers, heralded as later production machines than they actually were? This sort of thing is also known.
Suffice it to say that the GPZ305 was built until the mid-1980s, with styling appropriate for the time. He looked like a mid-80s superbike, sort of if you stood back and squinted. It came with a bikini fairing and other sports accessories.
The engine, however, was certainly not sporty. It was an air-cooled, 306cc, four-stroke parallel-twin, producing around 27 horsepower at 10,000 rpm and 19 lb-ft of torque at 8,500 rpm (depending on who you ask). Not bad, really, sounds like the kind of bike that would be a fun whip on back roads, without the cheap chassis … and the fact that the engines had a reputation for terrible, terrible reliability.
The GPZ305 had one particularly significant weakness: a plastic gear in the oil pump, which had a reputation for stripping its teeth. Once this happened, the 305 engine lost its upper oil pressure, and shortly after, its upper end.
One of my old bosses actually had one of these bikes and said he caught the problem just in time, before his bike got grenaded for a weekend. At the time, I believe there was some sort of work-around or do-it-yourself solution that solved the problem; I don’t know how you are going to solve this problem now.
There were also other weaknesses. The camshaft was a cheap and shoddy design, and there were other weak spots in the lubrication system. A major weak point in the lubrication system is bad enough, but several points of failure? Yikes.
Better than you think
And yet, while many owners have had terrible experiences with their small sport bikes, other GPZ305 riders have found it to be a lot of fun if they are 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 a chain drive, which kept transmission maintenance to a minimum. The 305 engine had excellent fuel economy, and with a wet weight of just over 350 pounds, the machine was much lighter than the large-caliber four-cylinder of the day. Dual disc brakes come standard on many models (not on this bike in the photo, however), a groundbreaking innovation for a low budget 1980s bike. And again, the styling, albeit very dated. today (look at those skinny bike tires on 18 inch rims!) was perfect for the time. The suspension was sort of light, but it was adjustable, which is more than what can be said about some entry-level sports bikes today.
Like I said my old boss Rob Harris owned one, and despite his poorly designed engine, he rode all over Scotland on his GPZ when he was young. As for me, I have never owned one, but I almost bought a 305 several times when I was a child. These bikes were all over picking up dust in barns and garages when I was growing up in rural Prince Edward Island. With a speed limit of over 90 km / h, the little twin was perfect for the area. I clearly remember looking to buy one for $ 600 when I was in my early twenties; it was in perfect condition except for a small dent in the tank and a broken turn signal from an overturned stop sign.
Did I miss a lot or cleverly avoided buying a bike with a ticking time bomb engine? Hard to say, but if I had just bought the machine and put it away neatly, this pristine finish would have refunded me, if I kept it in good condition. 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-displacement bikes are selling very well these days, thanks to supply chain issues limiting dealer supply. With a history stretching back almost 40 years, these bikes are also becoming collector’s items in their own right, especially given their heritage.
You see, these machines aren’t just some cool ’80s eccentric. The GPZ305 is also the forerunner of a machine that really changed the motorcycle world. After Kawi canned the 305, he released the EX250 Ninja. Here he corrected the mistakes made with the GPZ; the engine was a reliable liquid-cooled twin, and until 2012, this mainly reigned in the entry-level 250 sportbike market.
Honda blew up that market with the CBR250, a machine that had implications for the global motorcycling scene that are probably not even fully realized today. Now we have the CBR300, CBR500, Ninja 400, R3, RC390 and many other machines in this entry level class. All of these bikes owe at least part to the EX250 Ninja, and this bike owes a lot to the GPZ305, which paved the way for small sport bikes.
As noted above, this machine is on sale in Hamilton, Ontario. The coronavirus pandemic would mean out-of-town shoppers would struggle to acquire the bike, but not impossible. If you are interested, send a message to the seller; these bikes are rare in North America, and particularly in the United States, where they were very short in the auction rooms. You may want to check the grease system before you turn it on, however …