considering a zephyr 750. some questions

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hugojose
Posts: 161
Joined: 05 Sep 2017, 00:43

Re: considering a zephyr 750. some questions

Post by hugojose »

bubba_zanetti wrote:
Alright, just some reviews i read and other people mentioned it like it was some sort issue. I assume these are a bit more reliable than the Z1 or Z2 which is why im opting for the zephyr
If the Z1 and Z2 are the original 900 and 750 fours, then the Zephyr 750 engine was a newer different design; the 900 (which got to 1100) was considered obsolete and phased out in the early '80s, but the Zephyr 750 was still sold in Japan in 2008.

The Z2 was really the 900 debored to 750 because Japan would not allow anything bigger at the time in their turf, thus it had to carry the weight of the 900 with less power. The Zeph 750 engine was originally a 650 in '76 bored out to 750 in '78, thus the Zeph engine came from the light side, not the heavy one.

…..and by the way, there are a couple of guys in the KZ rider forum (US) who claim having reached 200K miles on the old 650.
Freddy
Posts: 695
Joined: 06 Sep 2017, 11:06
Location: Sydney Australia

Re: considering a zephyr 750. some questions

Post by Freddy »

bubba_zanetti wrote: So suspension and maybe brakes, and the Z2 4 in 4 exhaust and tank/seat/cowl. A slipper clutch would be nice as well. I know it has enough practical power.

Although the RS has almost twice the HP for the same weight, a zephyr is just a lot cheaper and more traditional

basically this https://www.youtube.com/watch?v=P0wxPeyFAVk
Mistake to compare HP, torque is what matters. A Zephyr stock produces 42 fl/lbs torque @ 7,300 rpm. A stock RS produces 53 fl/lbs @ 6,500 rpm. With minimal effort I reckon a Zephyr can be lifted in torque to high 40's, so not much in it. The only real practical difference is a Zephyr needs to be revved harder in the correct gear to get up an 'boogy'.

Save you money on a slipper clutch. The relatively low compression I4 in a Zephyr does not produce much engine braking. You have to have changed down to either 2nd or 1st going hard into a tight corner for it to be an issue that needs managing (just feather the clutch).

As per a previous post, caution against changing the exhaust. The whole intake/exhaust system on these CV carby equipped bikes is a complete and finely tuned system. The intake, cam profile/timing, and exhaust were designed by the Kawasaki engineers to work together as an integrated unit. Change anyone of these highly interrelated components at your peril. The exhaust is not just a bunch of pipes to dump the exhaust out the back of the bike. Where the back pressure waves that ALL exhausts produce hit the engine was factored into the original cam and intake design by the Kawasaki engineers.
Last edited by Freddy on 05 Nov 2019, 06:28, edited 1 time in total.
andye
Posts: 71
Joined: 11 Sep 2017, 10:03
Location: Merseyside

Re: considering a zephyr 750. some questions

Post by andye »

The Zephyr Engine is a development of the Z650 (KZ650) from the late 1970's rather than the original Z900. It's a great engine for a retro, (It is retro).
Reasonable low end pull with a good spread of power & It will rev to the limiter no bother. (shims under bucket)
Basic maintenance is straight forward. Service Parts are still available from Kawasaki Dealers (in the UK at least).
They have a reputation for rust, because they weren't looked after. They were considered an alternative to a Suzuki Bandit and used as commuters.
Garaged, cleaned & looked after they will last fine. I also own a 2001 Triumph Legend and apart from the Frame paint (The Triumphs Frame paint is really good, better than any Japanese bike of the time) the fit & finish of the Kawasaki is as good or better. Tank/Wheels/Alloy/switches/electrics are all decent quality.
Frames can be painted powdercoated and rustproofed they are not bad.
bubba_zanetti
Posts: 13
Joined: 30 Oct 2019, 19:43

Re: considering a zephyr 750. some questions

Post by bubba_zanetti »

is there any drop in replacement forks for the zephyr 750? or would i be better off with a fork rebuild with the racetech emulators.
bubba_zanetti
Posts: 13
Joined: 30 Oct 2019, 19:43

Re: considering a zephyr 750. some questions

Post by bubba_zanetti »

Another question, how many here have the later year zephyrs? 95 and on. Anyone know the changes they made up to 2008?
Freddy
Posts: 695
Joined: 06 Sep 2017, 11:06
Location: Sydney Australia

Re: considering a zephyr 750. some questions

Post by Freddy »

bubba_zanetti wrote:is there any drop in replacement forks for the zephyr 750? or would i be better off with a fork rebuild with the racetech emulators.
You can certainly get something like a Traxxion Dynamics AK20 cartridge kit made up if your in the USA. Other drop in cartridge kits are available.

The Race Tech emulators with correct spring rates for your weight are another less expensive option. However they are VERY fiddly to set up and get right. They are not just a drop in and forget option (the main reason for people not having a positive experience). As they have to be pulled out to adjust it can be a rather messy and time consuming process to get right. And you virtually have to fit them yourself, so you know how to remove and adjust them. Fortunately there is a member of the Zone who is pretty knowledge on setting them up for a Zephyr 750 so that should mean much of the initial pain can be avoided.

A good set of rear shocks with rebound and separate hi/low compression adjustment is a must. That may make you want to question using Ohlins as I don't believe they have a shock that fits with independent hi/low compression adjustment.

Oh! and a quality (meaning 3 piece fully adjustable) fork brace is a must. Cheapest suspension upgrade (about $100) that can be made to a Zephyr.
Freddy
Posts: 695
Joined: 06 Sep 2017, 11:06
Location: Sydney Australia

Re: considering a zephyr 750. some questions

Post by Freddy »

bubba_zanetti wrote:Another question, how many here have the later year zephyrs? 95 and on. Anyone know the changes they made up to 2008?
Your profile doesn't say where you're located.

If its the USA you can assume anything after about 1993 is not a retro Zephyr. It is a ZR-7 which while mechanically similar is a complete different concept (now just an old 'modern' characterless bike IMO, sorry ZR-7 owners.

The rest of the world continued to import the Zephyr till 1996, the D1 model. That is the end of the line, and anything newer than 1996 is a ZR-7 (but in some places is still termed a ZR750 same as a true Zephyr for some reason.

I would not buy a ZR-7, as it is old but also has no charm or reference back to a Z1/Z900 like a Zephyr. People come up to me all the time and want to talk about my Zephyr (admittedly older folk). I can't imagine anyone coming up and wanting to talk about someone's ZR-7.
hugojose
Posts: 161
Joined: 05 Sep 2017, 00:43

Re: considering a zephyr 750. some questions

Post by hugojose »

In North America the Zephyr 750 only sold for 3 years; '91, '92, and '93. It was not a success as a 'retro' of the older KZ750. After that, it completely disappeared, until in 2000 we got the ZR-7, but this was not a continuation of the theme. It was a stop gap model against the success of the Suzuki SV650 until Kawasaki developed the Versys, a liquid cooled, 650 twin.

Because the 'antic' ZR-7 would have to go against a much newer liquid cooled bike, the engine was refined, being the main difference a tensioner for the primary drive chain, and a top cam chain guide installed on the head, instead of valve cover. The carbs also had throttle body sensors integrated into the ignition box....and of course the rear chassis was different, incorporating a single shock. Opposite the Zephyr, the ZR-7 was not to look 'old', it was supposed to look 'new'.

Factory kept designating them as ZR750x, only changing the last letter for year...indicating it was simply a repackaging of older model...………....don't know for sure, but the latest Zephyr 750 in Japan, probably had internals from the latest ZR-7 engine, (it was also black), but still looked like the old motor.
bubba_zanetti
Posts: 13
Joined: 30 Oct 2019, 19:43

Re: considering a zephyr 750. some questions

Post by bubba_zanetti »

I'm in USA. i understand it was imported from 91 to 92 in the USA. I'm not confusing the later yearmodels with a ZR7 at all. Stricly zephyr 750. I understand it was made in japan until 2006 or 2008. Reason I ask is because for the price some people want for a cleaner one here I'm thinking i might be better off just importing a newer one from japan for around the same price.
hugojose
Posts: 161
Joined: 05 Sep 2017, 00:43

Re: considering a zephyr 750. some questions

Post by hugojose »

Interesting...….if any one can manage that.
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