Kawasaki Z1B Slipping out of gear!

MudSweatnGearsMCs

MudSweatnGearsMCs

New Member
Hey Everyone!

Usually lurk around without posting anything but have a dire need for help!

Long Story short I have a Kwak Z1B that is being a naughty girl, she quite happily rides well but you just cant stick second gear. Ive noticed that you cannot shift into second without the engine running. Not sure if this is what is supposed to happen.

But when the engine is running i can select 2nd gear, problem is, if i use too much of the throttle it slips back out of 2nd and will go into Neutral or sometimes First.

Anybody have any experience with these Zed's?

Thanks in advance!
Ben.
 
could be as simple a fix as the circlip falling off the clutch rod

or i have seen worn fork or dogs on the gear

all means the cases need splitting

you can get specific info from the z1 forum
 
check clutch first, but it sounds like wear in the transmission.
You can pull the pan and inspect a fair bit.
Some is accessible behind the trans cover behind the sprocket, but if it is worn dogs on the gears themselves, then you've got to split the cases and pull the engine all the way down.


But check the clutch first, as it's easiest and *can* give you that symptom with the certain issues


I second the Z1 boards, as this is not terribly uncommon.
 
How can we possibly positively identify the precise cause over the internet via a vague description?
How is your world so Black & White when considering such complex interdependent systems?


I have seen several occasions and personally experienced a few others where the normal wear in the shift dogs was exacerbated with incorrect clutch adjustment/malfunction or misaligned shift shaft/incomplete travel.


I will continue to offer my opinion based on my 25+ years experience, and all are welcome to completely disregard it as they see fit.
 
Bozz said:
How can we possibly positively identify the precise cause over the internet via a vague description?
How is your world so Black & White when considering such complex interdependent systems?


I have seen several occasions and personally experienced a few others where the normal wear in the shift dogs was exacerbated with incorrect clutch adjustment/malfunction or misaligned shift shaft/incomplete travel.


I will continue to offer my opinion based on my 25+ years experience, and all are welcome to completely disregard it as they see fit.
Click to expand...
if you need the clutch to shift you don't know how to shift is what i am saying
popping out of gear or a gear selection not being complete is not a clutch issue, in fact it is impossible for it to be so
the clutch has zero connection with the shifting mechanisms
the ONLY function of the clutch is to engage/disengage power from the CRANKSHAFT
your other points are valid
 
Cheers for all your replies everyone!

Sorry Im Terrible at forums:

To who that asked if the clutch is the problem; im 98% sure that ive taken that out of the equation, I rode the ol' girl for a good 10miles today and its pulling strong in every other gear.

I have found however i can shift her into second providing i keep the revs to a minimum and if i slowly build up speed, and i mean reallllll slow i can get her going. It almost feels as if the gear isnt getting into its mesh correctly and skipping out.

Like mentioned im suspecting a fork problem now or possibly a shift dog. Nonetheless Im looking at taking out the lump soon.

If anyone is interested and if i remember to i will post up some photos of the box.

Thanks again everyone, all your input is appreciated! ;D
 
Dogs need to be undercut. Common problem for 2nd gear on a bunch of bikes. We had a guy in our shop some years back and that's all he did - undercut gears for drag bikes.
 
Quick update!

Got the lump out of the ol girl today; Flipped it over and popped the sump off to find quite a nasty looking black mayonnaise, after wading through that nastiness i turned my attention to the gearbox.

Fortunately getting to the shifting mechanisms on these lumps arent too bad, I managed to get to the forks and measured the thickness of the ends. Both Output shaft forks are within tolerance, but one is getting real close to its limit. Im thinking this may have a contribution to the box not liking 2nd.

I also tried to measure the channel that the fork nipples sit in ( in know thats not their real name but who cannot like nipples... ) But problem is i cant get my verniers in a space i can barely fit my fist in... So im looking at getting that out some magical way without having to split the cases.

Luckily in my cache of parts i found an old z1 engine. Not sure what year/model but from what i can find the gearbox looks like its been used in nearly all of the Z1's.

So here is my plan....

Im going to check this engines box one more time just in case ive missed anything. If im still not happy - in goes the new ( to this engine ) gearbox.
 
what you are looking for is rounded dogs and there will be witness on the coresponding dogs slots as well
 
xb33bsa said:
what you are looking for is rounded dogs and there will be witness on the coresponding dogs slots as well
Click to expand...

Coming to think about it, the dogs may well be rounded. I cant seem to see anything else wrong with the box, but then im looking at it from the bottom. Its a royal pain in the arse that i cant get it to shift into second without the engine running, but apparently this is common anyway.

Im thinking about going ahead with the swap, at least this way i can still ride her ( properly ) and get this one sorted for later building.
 
UPDATE:

Think i have found the problem, Ive seen on one of the gears that its almost like a double chamfer, after looking around other gearboxes i am pretty sure this isnt correct. Also took a look at the dogs and some are in a pretty poor state.

So i have now settled on replacing the box, got one coming in tomorrow! Hopefully this will sort it out.

Also here is a pic of what i saw through the sump.

Notice the top row middle gear, right side of the gear looks as if its been struggling to mesh.

 
the gear teeth are always engaged, all of them, all the time are meshed
what you are looking for is rounded badly worn engagement dogs they are the bits on the sides of the gears,they are the only things that mesh and unmesh
 
BSMoto. said:
Coming to think about it, the dogs may well be rounded. I cant seem to see anything else wrong with the box, but then im looking at it from the bottom. Its a royal pain in the arse that i cant get it to shift into second without the engine running, but apparently this is common anyway.

Im thinking about going ahead with the swap, at least this way i can still ride her ( properly ) and get this one sorted for later building.
Click to expand...

The Z1 wont shift out of first unless the rear wheel is moving. You can spin it in neutral and shift to second.
 
Xb is correct. The problem is common and it's worn/rounded dogs on the gear that engages second. The shift fork is probably also worn and blued by now. Replace or repair the worn gears.

R&D in FL did our BMW 1200 trans and it was perfect after. Completely fixed the way it spat out of second gear. FAst By Gast and a few drag race shops can also do the work if you don't find a perfect replacement trans.
 
xb33bsa said:
the gear teeth are always engaged, all of them, all the time are meshed
what you are looking for is rounded badly worn engagement dogs they are the bits on the sides of the gears,they are the only things that mesh and unmesh
Click to expand...

I stand corrected, gearboxes are really not my stronger area. Ive looked at the dogs and some do seem to be in a bad state, hopefully these new clusters will sort it out, I also noticed when i took the forks out and shifted the gears by hand, one was slipping out, actually the one with the worn out teeth on the pic. It would go in gear, start turning and slip out half way, gave the sprocket a good throw round and it jumped out. Must be that causing this problem, Thanks for all your help Xb its invaluable!

doc_rot said:
The Z1 wont shift out of first unless the rear wheel is moving. You can spin it in neutral and shift to second.
Click to expand...

Aware of that now, shame i couldnt get it to go in with the shifter, had to remove the forks and do it by hand like mentioned above. Thanks for the heads up though 8)

teazer said:
Xb is correct. The problem is common and it's worn/rounded dogs on the gear that engages second. The shift fork is probably also worn and blued by now. Replace or repair the worn gears.

R&D in FL did our BMW 1200 trans and it was perfect after. Completely fixed the way it spat out of second gear. FAst By Gast and a few drag race shops can also do the work if you don't find a perfect replacement trans.
Click to expand...

Im 99% certain now its the dogs, ive ruled out pretty much everything else to do with shifting now. I did measure the forks and they are in tolerance, and look to be extremely clean no blueing like you mentioned.

Also cheers for the recommendations, but i think the postage alone would end being false economy lol im in the UK you see ;)
 
BSMoto. said:
Also cheers for the recommendations, but i think the postage alone would end being false economy lol im in the UK you see ;)
Click to expand...

Maybe ask around on the OldSkoolSuzuki forums about who's a good machinist local to you. The GS/GSX's were another bike that suffered badly from worn gear dogs, so some of those guys will know who can do them.

Good thing is you have the gearbox apart so you'll just be paying for the die grinding, not the disassembly of the box ;)
 
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