Retrospective: 1974-1979 Kawasaki KZ400 Twin

1976 Kawasaki KZ400
1976 Kawasaki KZ400D3. Owner: Michael Lane, Kansas City, Kansas.

Nice little bike. Great for commuting, but entirely capable of a cross-country trip. This model was an answer to problems in the global economy. The dollar was devalued in 1971, with President Nixon taking us off the gold standard, meaning we had less money to spend on foreign products. Also, Congress was upping the import tariffs on lots of things, trying to figure out how to pay for the war in Vietnam. In response, Kawasaki decided to build a factory in Lincoln, Nebraska. This was not a real manufacturing facility, but more of an assembly plant, as the import duties on bits and pieces of a motorcycle were a lot less than bringing in a whole one.

1976 Kawasaki KZ400
1976 Kawasaki KZ400.

Kawasaki had been looking at the success of Honda’s little four-stroke twin, the CB350, which had modest performance but all the amenities Americans seemed to like, including an electric starter. Kawasaki’s R&D backroom boys put their heads together, drew up plans and came forth with a very efficient, if rather uninspired, 398cc vertical twin, with a 360-degree crankshaft, an overhead camshaft and an electric leg. In June of 1974 the first KZ400 rolled off the assembly line in Akashi, Japan, and a number of them arrived in the United States. But that was just the beginning, as the factory was turning out a lot more parts than those assembly line workers could use. Crates of them were going to Nebraska. In January of 1975 a KZ400 rolled off the Lincoln line with “Made in the USA” on the ID plate.

One should add that the price of gas went up 45 percent between 1973 and 1975, from 39 cents per gallon to 57 cents. Could there be a better time for a 50-mpg econo-bike to hit the market?

1976 Kawasaki KZ400
1976 Kawasaki KZ400.

The frame was a simple double cradle having dual downtubes, with a big, fat backbone tube meeting up with the cradle at the swingarm pivot, a very solid affair that avoided any notion of flexiness. Front fork was by Kawasaki, very much like a Ceriani, and on the inexpensive, non-adjustable side. Five inches of travel was good, with a 27-degree rake and trail of approximately four inches offering a very middle-of-the-road stance. The swingarm ran out 20 inches, bouncing along on a cheap pair of Kawasaki shock absorbers having preload adjustability and three inches of travel. Too soft, reviewers said.

Spoked wheels were both 18 inchers, the front carrying a 3.25 tire, the rear, 3.50. Braking was done by a single 226mm (10.91-inch) disc on the front, a 180mm (7.09-inch) drum on the back. As a polite reviewer might say, adequate. But this was not intended for sporting riding like the Z-1, and the brakes worked fine for commuter use. Distance between the axles was 53.3 inches.

The wet-sump engine was straightforward, being slightly oversquare with a 64mm bore, 62mm stroke. Of minor note was the chain-driven counter-rotating balancer system down in the crankcase, called “harmonic” by one reviewer. It did not smooth out all vibrations, but for anyone happy to ride at two-thirds of redline (9,000 rpm) it was entirely adequate. Commuters, the intended buyers, were not known as rip-snorting riders.

1976 Kawasaki KZ400
1976 Kawasaki KZ400.

The four valves, two per cylinder, were pushed down by a single overhead camshaft, and 36mm Keihin CV carbs fed high-test gas (preferred) and air into the combustion chambers, where it was compressed 9:1. The engine was rated by the factory at 35 ponies, which was usually measured at the crankshaft, not the rear wheel; on a dyno it was closer to 29. Respectable; good for an honest 90 mph. In 1977, with the fuel crisis in the headlines, the carb size was reduced to 32mm to enhance mileage figures a little. And the compression was raised to 9.4:1, which served to create roughly the same power output. Ignition was by battery and single two-feed coil. Starting was by button, except a kickstarter was there as a backup, as many Americans did not yet fully trust electrically powered gizmos.

1976 Kawasaki KZ400
1976 Kawasaki KZ400.

Primary drive was via a Hy-Vo chain, and then through a wet clutch to a five-speed transmission and chain final drive. The long, flat saddle was great for one person, a bit crowded for two. Looks were OK, with shiny chrome fenders and nice paint on the 3.2-gallon gas tank and side panels. Curb weight was a shade more than 400 pounds. The only complaint seemed to be about occasional oil weepage coming from around the head.

The number of KZ400 models expanded. The D series, the essential KZ400 that we have here, went from ’74 to ’77 and cost $1,170 in ’74. The cheaper S series, with a drum front brake and no electric starter, went for $995 in ’75. And for one year, ’77, there was the A model, with small handlebar fairing, saddlebags and luggage rack.

1976 Kawasaki KZ400
1976 Kawasaki KZ400.

For ’78 the D designation became a B, with a redesign in the head, a slightly different gas tank and mufflers, an extra gear in the transmission and the fuel tap getting a diaphragm. The low-price version stayed with five speeds and had a two-into-one exhaust. And there was the stepped-saddle LTD “custom” model, with cast wheels.

This modest motorcycle was also a modest financial success. Kawasaki ran a lot of entertaining ads focused on the commuter, one saying, “More fun than any car I ever drove.” This ’76 model, in the same family since new, is quite stock except for the MAC mufflers.

For 1980 the engine was bored out to 67.5 mm, a 10 percent increase in size, and received a new KZ440 designation, giving the basic design four more years of life.


      • Agreed, this bike would sell in record numbers this year as original. Any doubters should look at the Yamaha TW200 that’s been sold for the last 30+ years with almost no changes other than a front disc brake. Simple, quick, efficient and reliable are qualities that sell and the styling is still solid today.

      • As the owner of this actual bike, I would love to see it with EFI since the carburetors are the major downfall of this bike. You can ride it for a week and then it just decides to quite running right and the carbs have to come apart. I never seem to find anything particularly wrong but it always seems to run when I put it back together.

  1. I had a 77 model and rode the heck out of it when I joined the Navy. Got me all over the southeastern US of A. In the 2 years I owned it I put 13,000 miles on it. Sold it before I deployed.

  2. I bought one in 1976 when I lived in Ontario. It had the two into one exhaust. Had it for two years. It gave me no problems, however had trouble getting past 70MPH, and was a bit wheezy cruising at highway speed. Had to use the gearshift quite a bit to get the most out of it. Traded it on a 1978 GS550, which was quite an improvement. A very good bike though, very simple and worked well as intended. I should have put a windshield on it, might have been easier to ride at speed.

    • I bought one in 76 also. Mine did 90 mph easily and I had it to 100 mph a couple times. I lived in Michigan and rode it year round. It handled well in snow and 0 F temps. I wish I still had it today!

  3. Bought a ’78 ex demo bike in 1980. Did 35000 miles on it as a tourer/commuter/instructors bike. Sold it to buy a Commando – not the best decision! Saw it later with nearly 90k on the clock. Gave me a great deal of respect for Kawas – have owned mainly their triples & fours ever since.

  4. This bike was riddled with oil leak issues. In 78 dealers were instructed to swap out the head cylinder rods along with all the seals to stop oil from gushing out of the top end. The issue was largely addressed when the 440 came out, but the 400 had developed a reputation by then. Aside from the oil leak, it’s a good bike but in reality it didn’t match up to the cb350 in any way except possibly in the looks category. There are some fun vintage commercials featuring so three models ok YouTube.

  5. Hi I’ve got a 1976 z 400 in real green. All original specification with 9000 miles on the clock.. any ideas how much it’s worth please ? Thanks

    • I’ve seen A quality survivors (unrestored) get close to $4,000 in the past few years, metallic green is the color of choice for collectors (Kawasaki Green after all). I have a 1978 KZ400 in real green which is unrestored original near A quality 6,900 original miles. It was stored for 25 years by the original owner with a dry fuel system in his concrete floor machine shop – best barn find ever. Personally, this is one of the best bikes of the era and with a few factory parts swaps it can outrun 500s of it’s time.

    • There is a nice looking”75 in Redmond, OR this week w/2000 mi. asking $2k. I’m not enthused by the early model problems. Might offer $1250 for this one.

  6. I have a 78 B model with 11000 miles
    It sat ten years and needed a tank and carbs. But i used a rust remover and cleaner then an epoxy sealer inthe tank and replaced the CV carbs with the non CV tipe and single split cable.
    I look forward to many miles of enjoyment here in Wa State.

  7. I had a 1979 or 1980 KZ400 Standard. I bought a kit (Felpro head gasket plus the Kawasaki oil-rings) to solve the cylinder head oil leak issue before having an oil leak issue. Before making the repair, I consulted with a Kawasaki Mechanic and slightly increased the torque on the head bolts – zero oil leaks or other issues. The longest trip I took on it was from New Brunswick, Canada to Chattanooga, Tennessee. I put about 10,000 miles on it then sold it for what I paid for it. It was a very good bike for the money.

  8. In 2008, I bought a used 77 A luxury model, out of state of Michigan with the fairing and everything. It’s a reliable and everyday iron horse!
    It does have oil leak, speed not reaching 70 mph issues. I wonder if changing a larger wheel sprocket could improve the speed…
    Last week, the speedometer plate broke due to hi-speed vibrations and aging..,I guess, it’s a 42 year old iron horse.
    Over all, it’s a reliable bike, alway start on the first ouch on the button, a honey-do bike, and probably a good collections.




  10. I had one here in Australia around the time they first were on the market and had no trouble that I can recall. As has already been said, the machine came out as fuel prices were rising and the makers did claim the engine was happy with low lead fuels so I bought one, primarily to get to work but also for medium length trips on the weekend. Did not own it very long as I went on to buy one of the last 750 mach 4 two strokes which was almost a contradiction in comparison to the kz!

    • Yes 17 digits didn’t start until 1981, I had the same issue with the DVLA England. Engine number on front sprocket casing and frame number stamped on headstock. Happy riding.

  11. I bought the 1st year in Columbus GA. Rode all of Ga. And twice RT from Ft. Benning to upstate NY.
    Never had a problem with anything.
    I’d like to find one now.

  12. My very first bike- got it in ’77 or ’78. Rode it through the last year of high school & through college but sold it when I moved south. Sadly, my memories are so dim now that I barely remember it, except for a few rides w/my brother or my girlfriends on the back. Thanks for the memories!

  13. I owned a 75 and my wife and I toured on it. We put a fairing, saddlebags and big pack on the luggage rack. At 2 up it was a little slow on Wyomings mtn passed but we had fun on it. I never had any problems of any kind with it and oh the memories of cross-country riding with it.

  14. I rode a ’75 KZ400 from Ft Riley, KS to San Francisco in 4 days when I got out of the Army in ’78, humming along at 75 or 80 mph the whole way. When I got home and my Dad saw the bike he said my accomplishment reminded him of Charles Lindburg’s crossing of the Atlantic. That was my second motorcycle, first street legal. 17 bikes, over 150k miles on two wheels and nearly 50 years of riding, I still use the KZ 400 as one of the benchmark bikes when I’m thinking about which bike I’ll get next. Thanks for the review and fuelling some great memories.

  15. 76′ Kz400 in red was my first bike bought used in 79′ with 5600 miles on it. Rode it a lot and all over the place. It had 63,000 miles on it when I sold it in 85′. Simpke for oil change and bulletproof.
    Only issues I had more than once was a dead battery. If you forgot to turn of the toggle switch on the back of the head light then you had a no go nike upon your return to ride. I did this 7 or 8 times over the years. Longest trip was Cinicnnati to Austin, TX. It really was a great do it all bike and would wheelie easily.

  16. Here in the UK the Z400 was in the shadows of Honda’s 400 four and Yamaha’s RD400 and so has always been an undervalued machine. However, as a middleweight commuter and occasional tourer it aquitted itself well, was understressed and reliable. The oil leaks issue was sorted by the 1979 B2 model. Bought mine new in 1980, used it daily getting to work, then weekend rides here in Peak District National Park. It also toured around Scotland a few times (about 1800 miles in a week) with solo camping gear no problems. 40 years on and after 30 years of storage/neglect, the engine still runs and now sits on the floor whilst everything else is being restored. Electrics and bearings are in incredibly good condition but the suspension is really deserving an upgrade. As a group of friends we’re mostly scaling back from our 1000cc bikes and I’m convinced that the rebirth of this little gem will be ideal for my mature years – I’ll literally relive my youth!

    • Nice! I had one 77-79 here in the Uk. Just picking a Z400B1 up next week which is a running project. Will need tidying. I ride a 900 and 1200 Trophy and am looking forward to adding this when I want to scale back…

      • Hi Steve, how’s your z400 project doing? Did you get any spanner time on it over winter?
        My B2 is still in pieces, the cold temps held up the engine painting and front fork issues proved a “head scratcher” to solve. BUT that’s mostly history now and the rolling chassis is about to take shape again.
        Good luck with your return.

  17. I had a 77 it was the best bike I ever owned . I sold it and put the money towards a z1 that I still have today. Wish I still had that 400 too.

  18. My niece and I are refurbishing a 79 ltd with 4800 miles on it. It still had the original tires with air in them when we got it. Put in electronic ignition and ma uni carbs. We are doing the front breaks at this time and should have it on the road next spring.

  19. I had a 75 one, in England, bought second hand in 76. I had one serious trouble. The balance shaft is driven by a chain which only goes less than half way round a sprocket on the crank shaft. T The teeth on the sprocket wore out after about 30,000 miles, I think. The chain then jumped putting the balance completely out. The sprocket was part of the crank shaft and to repair required a whole new CS. Fortunately I was able to get a second hand one from a bike being broken at a low mileage. Otherwise the cost of new one was so high I would have scrapped the bike. The only other snag about the bike was a high frequency vibration which numbed my right hand on long journeys. The left was OK so I assumed the little extra grip needed to keep the throttle open made the difference. It took maybe an hour of continuous riding at a steady speed for this to happen.

  20. I got a 82 Kz440D ltd belt drive. Shes a wonderful bike. Only thing I changed was the handle bars, and tuned it. Solid 30-40 miles per gallon depending on my romping. 9k original miles too:). Plan to keep her forever haha.

  21. My 4th bike was a 76 KZ 400. I bought it in 1978 and drove it through high school. It made me a badass and was the key to picking up a lot of girls. (Lol I used to Armor all the back half of the seat so that the riders (girls) would have to hold on tighter. 😛)
    I had the oil leak problem so while fixing it, I shaved the top of the cylinders down to increase the compression. Being a Canadian version might have made it faster than a US version but I never had a problem hitting 100mph. I used to race against RD350’s but they were so much lighter and maneuverable that I couldn’t keep up, especially in the twisties.
    Now I drive a Kawasaki Vulcan S 650 but would love to find an old KZ 400 to restore. The Vulcan S is a great bike aside for the lack of rear suspension, but I’ve been riding it for 5 years now problem free and fun as hell to drive.

  22. I had I believe a 74 Commuter Special. No frills kicker only with no tach. Nice bike was a little hard to start at times. Only $795.00 during a big promotion. Just can’t remember for sure the year but believe it was first year of 400.

  23. I have just came across a complete and in very good shape ’77 A model with the front fairing and side saddle bags, luggage rack. It appeared to have been carefully stored inside and has only 6065 miles on the odometer (license plate dated 1986). I rescued in from a scrape yard for $150. Now I have something to work on this winter!

    • You and Me both, absconded (sic) with a 1974 without the nice accessories You mention. Please let My Daughters & I know of any cast off parts You may be $elling. Best Regards, Big Mike the Bike.

  24. I had two z400 in the mid 70s. Did the job but there were both plagued with oil leeks around the cylinder head and the frame was not up to a British winter and corroded badly.

  25. I have my mother’s 1977 kz400 that my father bought her brand new. He was tired of riding her on the back so he bought her the s… kick start only, front drum brake. It was my first bike on the road when I was 16. Rode it to high school and took it to South Carolina from Pennsylvania to pick up fireworks once. Since I worked at a motorcycle shop at the time I quickly got bigger, faster motorcycles and the kz sat in my parent’s garage for years. Then when my son was born I decided I wanted to restore it. New fork seals, tires, and a quick carb cleaning got it up and running. I’m glad I got it back on the road and it’s a solid runner with no problems whatsoever. Now it sits in my collection among Harleys, a royal Enfield a Buell and a KTM. With only 12,900 miles on it it’s still a blast to ride and I’ll keep it forever. I tell my little boy that grandma rode that bike cross country with pop pop from pa to the west coast and he doesn’t believe it! Great bike, for sure! Starts first kick and runs like a top! Thanks for the article!

  26. My Daughters & I just stole a low mile ‘75 ‘S’ Model. We are restoring it as a Father/Daughter Project proving once & for All it’s OK to get dirt under ones fingernails, especially when those fingernails sport polish. Youngest is Blessed with Down Syndrome & knows more about tools than most boys in Her High School. My oldest is in Engineering School providing R&D in real time. Wife is on board once She ‘discovered’ a Vintage Bike in the basement. Me? I’m an old Curmudgeon Drag Racer having the time of my Life with my most prized possessions, My Wife & My Girls. Darn Eyes are leaking all over the damn wiring diagram again. . .Thanks for Reading my drivel.

  27. I bought a 79 b2 brand new in 1981 for $1,056 out the door and rode it for 15 years and 46,000 miles without ever seeing a shop for repairs. Only problems were a starter switch, oil pressure sender unit and headlight replacement. Only modifications were a k&n air filter, Kerker 2 into 1 exhaust, and a shoei sport fairing. Top speed was 106 mph consistently and could pull wheelies easier than my 550 Suzuki. In 1996 I repainted the tank, side covers, and tailpiece royal blue since the original firecracker re paint was fading to gold. Better than new when I sold it. Would I buy that bike again? In a heartbeat!!


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