The Kawasaki Z750 Twin

Nobody loved it… till now.

What is it?

It’s a 745cc, 360degree air-cooled parallel twin, made from 1976 – 1984

What sort of bike?

It had no pretensions of being anything in particular, just a bike that goes. It didn’t try to appeal to any single group, which inevitably led to its not appealing to any group at all, and sales were dead on the vine. Because of the engine type, it was compared to both the Triumph Bonneville and Yamaha XS650, though not to Yamaha’s XS500, although I’m sure the reviewers had this bike in mind at the time (high-tech[!] twin, DOHC, balancer shafts) which was famous only for its unreliability, and was a similar sales disaster.

With hindsight, it was the first Japanese cruiser.  Caught on a cusp between engineers who wanted their bike to go round corners, a modern Bonnie, and marketing, who needed something to compete with the Harley, they came up with the Z750 Twin.  Chopping bits off the Z1 and rescaling was simple, after all.  And so the bike fell between two stools, and boy, did it fall.  These days, the genre has mostly been defined as slow, heavy and V-Twin powered.  2 out of 3 ain’t bad!

What’ll it do mister?

It’ll start, probably off the kick-start as the electric foot isn’t even an electric inch.

It’ll go faster than the traffic, except on motorways, whilst making a gorgeous burble through any non-standard exhaust. It will do this for some considerable time, since it’s not prone to chewing chains/tyres, and will actively discourage thrashing (more later). Getting you there and back is all it’s for, and it’s very, very good at that. A properly set up one will have less vibration than a four, and the handling is way better than any Harley-rep cruiser.

It will also have old men at traffic lights telling you that it sounds just like their old Triumph (which it does). Depending on the mood, you can either engage in a long and pointless conversation or just stare fixedly into the distance. Any more would be rude, and we can’t have that can we? 🙂

It will keep your pillion happy. Well mine anyway. Her bum is still soft and pliable after milesandmilesandmiles. She still complains, but that’s what other halves are for huh?

It will spray your right leg with oil. This is a problem with the tacho drive seal, and is a ‘feature’ not a fault!

It will look good. Beauty is in the eye of the beholder, but to my personal eye this is exactly what a bike should look like, and looks are the starting point of any proper love affair.  Flowing, curvy lines with a huge chunk of engine in the middle. No plastic, no pretentions. They really don’t make them like this any more. Zephyr? Don’t make me laugh.  W650? OK, a good bike, but not exactly unpretentious, is it?

It will sound good.  This type of engine fires once per revolution, which is just inherently right, and will sooth the soul.  A 2:2 exhaust is mandatory, otherwise it will sound like Superdreams big brother, and you don’t want that.

Oh, speed. About 105mph. But not for long. Too many 14.2 standing quarters will destroy the clutch.

What won’t it do?

It won’t keep up with anything bigger than a 500, and the only thing less likely to be found at a track day would be a Cossack Urine. It doesn’t do fast. It will whinge at sustained revs over 6000 (90mph), and will ultimately overheat. Enjoy the relaxed burble and watch the world go by peacefully, safe in the knowledge that your licence will be yours forever. It’s touring range is limited only by fuel stops, since reserve will kick in at an extremely irritating 100miles, when your bum only goes numb after about 400.  The fuel tank size is the only thing that Big K got really wrong with this bike.  That and the tacho drive seal.  There were TWO things that Big K…

It won’t do stoppies. The single front disk was a standard fitment to Kwaks throughout the 70’s, and was always weak, and positively lethal in the wet. The bike came with mounts and fittings for a second disk as standard, although I’ve never seen a twin-disk model.

It won’t do street-cred, but small boys do seem to like the noise and presence of a near-on 500lb(230kg) lump of chromed metal. The commonest colour (shit brown) doesn’t exactly do it a lot of favours either.

It’s old, it must be knackered.

Probably.  It comes complete with some favourite Japanese stereotypes, the main one being a camchain tensioner which is prone to doing MUCH more harm than good.  The electrics will almost certainly have been bodged by some nerk armed only with insulating tape.  The shocks will be rusty, and usually empty.  Neutral on the early models was as elusive as an honest politician, the late ones have a positive stop to fix this.

The electric starter WILL NOT WORK. Working starters are rare enough to elevate a machine to concours condition on this one point alone.  Two reasons for this: the first is that they’re really not up to the task of turning 2 big cylinders (the starter was also used on the Z650, a much easier proposition) and second that the starter clutch often fails, either spinning the starter into oblivion or making a sullen schhh noise as it fails to engage on the engine.  NOS starters are, amazingly, available on eBay from the States at sensible prices, even including shipping.

The inlet manifolds (carb holders in the US) wear out enough to be considered consumable items.  If your bike is blowing and spitting, these are prime suspects.  Get NOS ones from anywhere but the UK. 16065-036.  I know that number by heart, and have an ebay search on it.  The problem seems to be overtightening of the jubilee clips causing the rubber to split at a shear point.  So don’t do it.

If it still spits and farts, look at the float height.  V. difficult to check, and a pain to adjust and get right, but these 38mm Mikunis seem to be critically affected by it.  Took me ages to suss that one, but could well be borne in mind when haggling with the owner of an old dog that sounds like a drag bike at idle.  Get it home, do the carbs and manifolds, a quick balance by the piss-easy technique of putting your hand over the pipes [not the 2:1 :)] and you’ll be smirking everytime you get on.  Make sure you put the throttle cables on the right way round though…

These bikes don’t vibrate.  If you’re looking at one that does, walk away, very quickly.  You don’t want to be messing with those balancers.

It’s saving grace is probably its nature and a 4 litre sump.  Together, they combine to produce a bike that isn’t often thrashed and can survive the inevitable oil-change neglect.  Underuse will cause more problems than a daily hack to work.

It’s common enough stuff though, the engine and cycle parts are pretty damn simple really.  Spares are non-existent in the UK, but quite common in the US, which bought quite a few coz there was a Kawasaki plant there.  Handy if you need something really complicated like, say, a clutch cable.  The workshop manual is a total gem, and gives good stuff that relates to most bikes, especially about the electrical system.  It is to Haynes as John Robinson was to Steve Berry.

What’s so good about it then?

As I said, the looks are the starting point. The bike is effectively a Z1 with the engine cut in two, and it shares most of the cycle parts with its bigger brothers. It’s heavy and it’s planted. It handles.  No, really!  The road bends, not the frame. OK, so she needs a bit of man-handling, but if a thing is easy, it’s not worth doing.

Then there’s the sound.  When it echoes between the claustrophobic walls of the terraced houses round here it is truly evocative. The point about the engine is that the sound is even, not like any V-twin, and an inline 4 can’t come close, no matter how loud. Pobbling around town at 1500 in top, it’s happy. It’s a biking St. Bernard; it’s big, it’s strong, and it makes its point in an unconcerned take-it-or-leave-it way. Wanna go faster? Just open the throttle, no gear-changes necessary. Which brings us to…

Bit of a wuss isn’t it?

Yep, can’t argue really. Your CBZFX600 can blow several shades of shit out of it, given enough revs. But’s that’s it you see. We don’t need revs in Big Twin country. With roads infested by speed cameras, a machine that chills you out the moment it starts is a positive benefit. The engines only rated at 55chevals, but the torque is there from tickover, and never changes.  Besides, those 55 nags will be with the stock exhaust system, and anything even moderately fruity will open a few more stable doors.  After all, the legendary Z1 alleged 20bhp per 225cc cylinder, so 30bhp from a 375cc version of the same cylinder is hardly too much to ask. Still only sixty ponies, but they all pull together, all the time.

Yebbut it’s still SLOOOOOOOW!

In biking terms, it’s a dinosaur and behaves like one. But tell that to the Ford Focus which hasn’t crossed the lights by the time you’re at the next roundabout. Relativity my son, relativity.

OK, if it’s so good, why does it rate a specific mention in the uk.rec.motorcycles.classic ‘Bikes to Avoid’?

Two reasons:
First, not many people have ridden one, and some of those will have come across the SOB version which has completely knackered every chain in the machine.  If it’s not fettled, the bike will vibrate like a 500lb dildo, which might be fun for a while, but quickly gets a bit sore!

Hate mail

Second, when it came out, the bike got panned by a bunch of overpaid, overindulged reptiles who said that it lacked ‘character’. Saddled with EPA fuel emissions bollox and silenced to buggery, character was always going to be at a bit of a premium on a bike that had no past to nostalge on, when it was in competition with the (equally ruined by that time) Bonnevile and that flat-track favourite, the XS650.  All you could hear was the chains rustling, so they fretted about them.  Damned with faint praise as it was, the poor bugger never stood a chance.  The reputation has survived long after the bike it killed, like fungus on a tree.

And suppose I actually want to buy one?

Genuine UK models aren’t common.  They didn’t sell many, so there’s not many left, see?  What there are have mostly been left to rot in the dungeon of Chopper-dom, or Bob-ness or some such travesty where Custom usually means ‘exactly the same as everyone else who wants to do a bike up’. There are however a lot of US imports.  I don’t really understand this, as it would’ve meant paying a huge freight cost to ship a large chunk of metal that no-one here wanted in the first place. A US model is most easily sussed by the rear mudguard (remember them?).  Living in a wet and dreary land, our mudguard is longer than theirs.  If it ends level with the rear spindle, it’s a UK one.  Obviously US versions also had higher bars, but they are easily changed.

Check the brakes carefully.  As well as being prone to seizing, I’ve had problems where the pressure operated front brake light switch started to ‘give’, causing a spongy and completely inadequate brake.  Later models had a flat rectangular master cylinder, probably to accommodate twin-disc setups (which didn’t happen until the dedicated cruiser models). It’s more powerful but has less feel than the classic circular one.

Check the swing-arm.  A loose swing arm will give er.. interesting handling, and will probably need an engineering shop to make new bushes.

There will be a grinding noise from the clutch when you start off from cold.  There will  be, and it should  go away.  The clutch is not this bikes strong point.

As I’ve said, if it vibrates in neutral, leave it.  If it vibrates only on the move, it might well just be the chain.  As with all bikes, a chain and sprockets are real money, so haggle, bearing in mind that the bike has had the sort of owner that not only runs, but sells a bike in this condition.

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