ZZR600 Gearbox problems Solved i Think !!

[mouse_zzr600]

Hi all
i have some serious ZZR600 Gearbox problems.
History first.
I bought bike new in 2000 and at 21000ks i had an issue with a phantom neutral and 5th gear popping out.
Took bike back under warranty, was told not covered due to wrong oil ( synthetic penzoil the bike shop serviced it with ) and rider abuse, so no claim. I got screwed.
I am a pussy rider as it is my main form of comuting to work so why would i abuse it ? I regularly service at 5000k intervals ( now with a non synthetic oil due to my type of riding ) and generaly change between 4-5000 rpm sometimes with clutch sometimes without ( maybe where my problem is ?)
I am a car mechanic so performed repairs myself with new gears, selector forks, Shift drum etc. cost me a fortune
The bike now has 72000ks on the clock and been a very honest, daily used machine with no real issues until recently.
I now have developed phantom neutral in 4th same symptoms popping out of gear as at 21000ks.
My question is Have i missed somthing in the previous repair i performed back in 2001 or is it a problem with this model having a realitivly soft transmission..
I have stripped down again and found same thing rounded dogs, serverly worn shift drum and serverly worn and torn selector forks etc. I have procured a complete s/hand transmission but need to know if i have missed somthing.
I am concerned coz i dont want to have to do this a third time
Any help would be appraciated thanks
Regs Mouse

[Strika]

I worked in a Kawasaki shop and saw loads of high mileage ZZR6's only one of which ever realised an issue. It was 2nd gear which went. But it wasn't common. The ZZR6 box is known to be clunky, but not to do 4th's and 5th's??? I've seen loads of these bikes with 100,000klms plus on them without box issues! Why yours is gone, I can't explain? Bad luck maybe? 20K from the first box, 50k from the 2nd? At least it's getting better!! Maybe try another box and you'll get 100,000 out of it!

[Head_Mechanic]

I am a pussy rider as it is my main form of comuting to work so why would i abuse it ? I regularly service at 5000k intervals ( now with a non synthetic oil due to my type of riding ) and generaly change between 4-5000 rpm sometimes with clutch sometimes without ( maybe where my problem is ?)

Do not use synthetic pennzoil use a proper semi synthetic bike oil . Some ZZR 600 boxes do jump out of second gear and they will have a false neutral some times . what revs you change at wont make that much difference but changing with out using the clutch will . some people can do it and some just put a lot of strain on the gear box. I have a 1992 zzr600 with 87K on it and the box changes perfectly . Another thing that my play a part in your problem is the chain, to loose or to tight and you will put unnescary load on the gear box .
Reg

[Russell]

My 02 ZZR600 is up to 62000 k's now and the only time I get false neutrals or missed gears is when the chain is loose or the oil needs changing. My bike generally gets Motul 5100 (or Motul 5000 for a while there). I usually use the clutch for changes but sometimes don't. I'm not a gentle rider (quite often I'm quick changing up around the 10k rpm mark and above) so the box certainly isn't "soft" on this model in general...

Any more information you can give about the way you ride or the oil you use... or anything? Seems unlikely that its something you did in the repair - more likely its something you've been doing since then?

[mouse_zzr600]

My 02 ZZR600 is up to 62000 k's now and the only time I get false neutrals or missed gears is when the chain is loose or the oil needs changing. My bike generally gets Motul 5100 (or Motul 5000 for a while there). I usually use the clutch for changes but sometimes don't. I'm not a gentle rider (quite often I'm quick changing up around the 10k rpm mark and above) so the box certainly isn't "soft" on this model in general...

Any more information you can give about the way you ride or the oil you use... or anything? Seems unlikely that its something you did in the repair - more likely its something you've been doing since then?

OK then, maybee my bad. Altho it doesn't explain my orig failure at 20.000ks when i was more perdantic about it. I do have a habit of feather clutching when changing gears and am a bit slack on chain adjustment however a bit of history on my style of riding and maintanance.
I travel on average 30-40ks per day to and from work, with an occasional blat down the freeway for a couple of weeks to work with a return trip of 100km. ( at these times i average 1000km per month for a couple of months ) and occasional rides out and about.
The bike, imo, has never been thrashed ,is a virgin to mono's, and never been droped. I change oil every 5000ks or so and filter every alternate change at 10.000, along with air filter service and plugs. I use Shell S4 20w-50 oil , which was recommened to me ( by numerous bike shops ) at the first failure and have ever since. I average between 250-300ks per tank of fuel ( before reserve ).
I average 20-25000ks from Bridgy Batalax BT014,BT020 tyres,Green backed stoppers ( brake pads ) and D.I.D. X-Ring chain ( which i use TAC2 chain lube every 500ks or so depending on weather ) and sprockets ( with an alternate ratio of 16f and 45 rear ) but i am slack in adjustments. I tend to wait until it becomes noisey before i adjust it. Like i said in my orig post i am somewhat a pussy rider ( compared to a lot of others ) and may well be classed as a soft c**k or woos, however i do enjoy riding for what it is. Keeping in mind it is primarily used for commuting in heavy traffic.
Maybee this is my problem, i don't ride it hard enough or abuse it
Hope this helps Regs Mouse_zzr600

[DaveGPz]

My wife's ZZR600 is a '97 with 60K - most put on in the last 4 years (about 10K/year) and no gear box problems (except for being clunky into 1st); it's done a few trackdays at Phillip Island (before she got it) and is an all weather commuter into Melbourne 5 days a week (about 50k/day), plus touring whenever possible. I use Motul 5100 10W-40 on both bikes, changing every 3000 - 5000 depending on use, and the filter every 2nd change. But the chain is checked weekly, and adjusted as soon as freeplay exceeds normal range. Maybe the chain tension's the trick - they really don't like too loose or too tight, but I never thought it'd kill a gearbox the way you've described! Good luck.

[Russell]

Yeah, its a mystery to me too. Mine does 3 trips to work (110k round trip) each week in all weather, I change oil and filter every 5000 but have occasionally been slack and it's been about 7 or 8,000 a few times I'm also pretty slack with my chain lube, but when the chain adjustment is happening every two weeks it gets replaced.
I also run the BT014/BT020 combo (well, 021 now since the 020 has been replaced) and I'm lucky to get half of what you're getting outta mine, so that gives you an indication of what sort of treatment I'm giving mine...

Maybe the chain tension is the thing, but I can't believe it would trash a box like you're describing. How old is the second hand one you got and what condition is it in? Does it show any signs of the same sort of wear at all?

[mouse_zzr600]

The original failure ( at 21.000ks ) was repaired using all new Kawasaki items.
The replacement this time will be with one i beleive to be out of a later model low k unit.
My belief is it had approx 35000k on it ( who knows, its from a wrecker and they are not curtain which bike it came from lol ).
It sure shows no sign of any of the type of wear mine has so heres hoping.
Update on condition of my orig gearbox, the meshing parts of the gears are 100% ok. It is only the dogs that have screwed up . The shift forks are trashed on the sides sugesting to much freeplay somewhere ( shift forks have been rubbing on the gears themselves and not in the area where the forks run ) and there are gouges in the shift drum at the point of positive selection ( if you know where i mean ). I stripped down the gear sets thinking maybe a mainshaft bearing failure however all appears to be within spec. I also found 2 of my clutch plates to be well beyond the servicable limits ( 2.62 as opposed to service limit of 2.90 ) sugesting maybe my clutch has not been relieving the load on the box during gear changes and giving an incorrect pressure when disengage ( clutch slip ).
Maybe all this and my slackness in chain adjustment are contributing factors. Only time will tell i supose.
The box is now together and engine is now back in frame waiting to be finished being put together.
If someone can assist me in posting some pics ( if anyone wants to see the evidence ) i will gladly oblige
{ edit to completed stage }

The Bike is now back on the road and is better than it ever was since new.
All gears perform without the usual " clunk " even in 1st.
So with that said maybe the clutch is the key. I have ridden some other zzr6's recently that have new clutches in them and they are the same " no clunk into 1st " and the symptoms for replacement were clunking gearbox into 1st, unusual rpm's at freeway speeds ( ie: 5000 rpm at 100ks at one time and then 5500 rpm's at 100ks etc. ) and false neutrals at any rpm.
So with this and my slackness in chain adjustments i think i may well have my problem solved. Only time will tell
Thanks to all who have helped me and your advise it has made me beleive in Kwaka's again

Thanks again Mouse_zzr600