Kawasaki KZ750

Under the radar

| March/April 2009


Kawasaki KZ750

Kawasaki KZ750
Years produced:
Total production: N/A
Claimed power: 55hp @ 7000rpm (1976)
Top speed: 103mph (period test)
Engine type: 745cc OHC, air-cooled parallel twin
Transmission: 5-speed
Weight: 504lbs (w/half-tank fuel)
Price then: $1,975 (1976)
Price now: $500-$1,750
MPG: 45-55

If ever a machine was worthy of Under the Radar status, it’s the big twin Kawasaki KZ750. Never heard of it? Don’t feel bad, because the truth is, most people haven’t.

Introduced in 1976, the KZ750 was the odd-man-out in Kawasaki’s lineup, especially considering the new bikes Kawasaki had planned for 1977, which included the 4-cylinder KZ650 and KZ1000. Matched up against those two machines and the carry-over KZ900 four, the 750 didn’t quite make sense. With its legendary 2-stroke triples a thing of the past, Kawasaki’s performance machines were being defined by four cylinders. So why a big twin?

The vertical twin
Before the onslaught of big triples and fours, the 750cc category was pretty much defined by vertical twins; or more to the point, British vertical twins like the Royal Enfield Interceptor, Norton Commando and Triumph Bonneville. Yamaha made some motion into the category with the Yamaha XS650 vertical twin in 1970, and even more so with the Yamaha TX750 three years later. But compared to its British rivals the XS650 was considered small, while the TX750 was a regrettable failure. By the end of 1975, there were really only two large vertical twins on the market, the 750cc Triumph Bonneville and the 650cc Yamaha XS650.

Looked at from this light, Kawasaki’s move made sense. While the days of Rule Britannia were over, there was still a sizeable community of riders who wanted a big twin. For that group, the new fours were too much. They had two too many cylinders, too many camshafts, too many carburetors and too many spark plugs. For these riders, the best bike wasn’t defined by quarter-mile performance, it was defined by ease of maintenance and dependability. And on that score, the KZ750 delivered.

Unlike Kawasaki’s last big twin, the BSA-clone W650, the KZ750 was thoroughly up-to-date. The 55 horsepower, 745cc twin had double overhead cams, shim and bucket valve adjustment, a Morse Hy-Vo primary drive chain and five forward gears. Vertical twins vibrate, so Kawasaki gave the 750 a pair of chain-driven counter balancers. It worked — mostly. Although smooth at low and moderate rpms, period testers faulted the twin for a distinct buzzing at anything over 4,000rpm, and feared it would shake itself apart at anything approaching its 7,750rpm redline: It wouldn’t, it just felt that way.

3/10/2016 4:00:23 PM

Damn this website is terrible! 3rd try to post this. Ive got 2 KZ750Bs. One i got from a shop customer in trade for money off his bill on a Triumph build back when I had a shop, Used it a rat bike and loaner for friends for several years. Sidelined when those dang CV carbs went south (Swap them out for a Mikuni CV carb set) Got another with a few missing parts but a runner a few years ago. Putting together a cafe racer styled bike with Airtec body work See: http://www.airtech-streamlining.com/kawiz/H1H21969-76.htm And going to paint it the funky Kawasaki mean green paint. I got some NOS aftermarket 2>1 pipes and has a nice shorty muffler, Not the fastest thing on 2 wheels but it will look like it. I was always surprised not much out there for performance upgrade parts. I would think a Camshaft kit might wake it up nicely, but for the most part, These are very reliable bikes.

10/21/2015 5:19:47 AM

just aquired kz model kawasaki and am confused, was told it was 750 cc but also a 70s model now i knew of 650cc models growing up but this is a 4 cylinder i have a photo but don't know if it is possible to get it to you my computer skills are as old as my m/cycles .dennis australia.

2/9/2015 7:06:15 AM

Just acquired '76 KZ750B with 12K miles. For being almost 40 years old, this reliable old Big Twin runs and shifts like a champ. Will soon be locating and replacing "hidden" oil filter. Someone installed cool looking chrome mufflers which do a good job but block operation of centerstand. This bike has lots of power and is famous for reliability. I love the sound and the heavy weight (520 lbs). Really different. BTW I've owned 20 motorcycles over almost 60 years of riding and enjoy this old KZ very much. Jerry Central Florida

5/8/2014 9:24:09 AM

Here's my two cents' worth: Love my KZ750B. With new tires and a Corbin seat and the previous owner's orange/flame paint job, this big ol' bike gets old-school riders pumping. Starts on one or two kicks, which is good, since the starter clutch (same part as in the tiny KZ400) is weak. Had several Yamaha 650s, and like the looks, but not much else. Easy starting, but their bad handling is made worse by modern tires, which afford too much grip and torque the chassis even worse. Uncomfortable to ride in any mode, they're best parked outside the cafe. Didn't have an R80, but the R75/5 I bought for my Dad was fast enough and comfortable enough and totally reliable. It was just so tall that neither he nor I ever liked it too much. He preferred his 305 Dream, and I much preferred my R69US.

Nick Howell-Ives
1/7/2011 11:12:04 AM

You were correct in every respect; Last year I found my beautiful, original condition 1978 KZ750 discarded in a garage. Having seldom seen the light of day since she was imported to England from USA during, I think, the early 80s she required only minor repair; battery, starter clutch, tyres and brakes. 27,000 miles, 350 USDollars; no other stats needed. Certainly as much fun as any machine I have owned in over 40 years road riding.

Brent Schapansky
5/5/2009 1:46:45 AM

I'll shout out a halelulea (or whatever) to the end of that article. I traded a wrecked car to a country auto wrecker here in northern Alberta for a '76 KZ750 B1 last year. I also got a '77 KZ650 Four basket case for parts. After about 14 months, the old twin is 90% complete, needs only a set of pipes, a new ignition switch and a new battery and paint for the bodywork. It has the swing-arm and rear, and front end, from the 650 which was a C1 so dual front disks. The 750 has 42K miles on the odo and was said to be a good runner. I fired up the engine sans exhausts, while it was on the bench. It fired up after about 3 cranks of the starter and as expected, was LOUD :) but ran nice. I ditched the stock seat, rusted out pipes and mufflers, rusty spoke wheels (650 gave up nice cast alloys) and horribly uncomfortable stock bars for horribly uncomfortable Clubman bars, a custom seat, shortened the parralel portion of the seat section of the frame by 6 1/2 inches, keeping the stock cowl and rear light mounts and I gotta say, it looks pretty sharp, even in primer AND, it is 97% factory parts, even if only 60% stock. The Lonesome Twin lives on! Brent in Peace River, Alberta, Canada

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