Zxr750 j1 issues. Help and moral support please :)

[robz]

Hi all.
So my zxr750 is having issues.

1 - it's leaking oil around the slave cylinder. So I have a rebuild kit for that on the way. It's making my clutch slip now too. I think cos it's not allowing the cylinder to fully return.
Is there an oil seal on the push rod? I can't see one?

2 - I'm only getting 100 miles out of a full tank of fuel? Is that about right?

3- the idle is a nightmare. Keeps either revving it wanting to stall. It's fine riding but idle is poo.
I'm wondering if it's due to the clutch issue so it's still partially engaging hence the wonky idle.?

Any help appreciated!!
Just tell me I haven't bought a lemon please haha

[z900/zx9]

Firstly 100 miles per tank is not normal,as for the idle that could be a number of things,firstly check that the manifold rubbers are in good condition without any air leaks.
Good luck.

[pkay]

I have a H1 and I get about 240Km on a tank so 100 miles for a sick running bike may be about right.

The idle issue is unlikely to be related to the clutch issue - unless the clutch is semi engaged its just likely to slow the idle and burn your plates. But as you have to fix this do that first then set your idle speed properly and see what happens.

Firstly make sure you set your idle speed with the bike warm - I have had many issues with bike shops not doing this - they do it with the bike cold and it will rev its tits off when warm. If this doesn't solve your problem check for air leaks between the carbs and the block - take thetank off and use a torch you'll be surprised. If the rubbers on either side of the carbies are hard then you need to address this (new ones or boiling in wintergreen oil if you want to recycle). If thats ok check the other side to the airbox as well. If that's not it I'd suggest getting the carbs balanced to make sure they are all sucking in tune. If that doesn't work check the insides of the carbs especially the low speed circuit. (I've tried to suggestthis is an order that avoids pulling bits to pieces as the last resort but you may want to go the other way to sort the whole thing out anyway).

[robz]

hi all, thanks for the reply!!
sooo...
i re built the slave - the old seal was defo knackered!
so this am, first ride out - no leaks after i turned off, so seem to have solved this.

the problem is now the idle is still crap, but also the clutch is still slipping under load, but gets worse as it gets hot i think.
when i re bled the clutch, the lever had a notchyness at the end of the throw, so could it be not moving freely and giving me a slight burn when in gear and slight slip when released?? funny really cos the ride to work this morning was fine, then the ride home was aweful? would a faulty master cylinder cause this, cos it was a bitch to get the air from that to get it to start taking the fluid from the reservoir!
it was a total beep to ride home today, nearly dropped it cos i couldnt find a reliable bite.
all this was fine till i started trying to sort the small leak, so surely must be something i have done???

otherwise this bike is awesome, but i really havent enjoyed riding her this week

all help massively appreciated!
i really want to start contributing to the forum with porny pics in the countryside at a weekend but this is properly stopping me!

[pkay]

Did you use a syringe or some thing to suck the air out? Getting all the air out can be a total mongrel. But air will have the opposite effect in that the clutch will stick as you will not get enough pressure to move the pressure plates. Slightest bit of air will make it crap. I now use a bleed kit for that reason. Have you looked at the clutch condition and also your oil?

[robz]

Yes I had to use a syringe. Wouldn't get it to start bleeding otherwise. Was trying the normal way for over an hour first time.
I re bled it yesterday and the lever feels better.
About to go to work. Fingers crossed it goes ok.
I think all the air is out now.
I've not dropped the oil as yet. Or looked at the plates. Purely because the bike was perfectly fine before I fixed the oil/fluid leak haha

[robz]

So I have a slippy clutch still.
So frustrated.
As far as I can tell it's bled with no air still?
To me it doesn't seen to be disengaging properly either. I can't free roll the bike in gear with the clutch in easily?
Would a broken spring cause this?
Cheers

[pkay]

I suspect that you'll need to take the cover off and have a look at the cutch plates otherwise you'll be chasing your tail and get frustrated. Also an opportunity then to do the oil and get a clean start. The fibre plates aren't that exe and I'd also check your metal ones are true (use a metal ruler or feeler gauge to check how flat they are). You can also check your springs while you're there. The manual is really good at explaining how to check their condition and wear. And if you're careful you should get away without having to re-bleed the clutch.

[robz]

well blow me, played around again last night and now i have a slipping clutch and the oil is back leaking.. cant win here!

[z900/zx9]

well blow me, played around again last night and now i have a slipping clutch and the oil is back leaking.. cant win here!

Ok this may seem like an obvious thing ,are you running a full synth oil ????. Pretty sure some clutchplates might not be so keen on this.

[robz]

Not sure.
I've not put the oil in. Previous owner did.
If I get to the point of pulling the clutch cover off I will replace it with the right stuff.
Doesn't explain why it's slipping all of a sudden either ?:(
I measured the pushrod, it's 3 mm shorter than a new one I asked about. Could this be a problem?
Cheers

[mick12]

here is a bit on the bad idle as others have mentioned air leaks a good thing to check are the intake rubbers some cracks are hard to see as the clamps themselves will cut into them and be hidden by the clamps even more so if the clamps are the cheap wide ones from an auto shop best to remove the carbs and rubbers for a good look i had a similar prob on an old gixer and didnt find it until i took them right off and found they were just about to fall apart on the bike you couldnt see a thing wrong with them

[robz]

Thanks for that!! Will be looking at those then. Hopefully nothing too bad!
Ok. So. After a rubbish couple of weeks I've got somewhere.
Ended up replacing the bad looking slave seal. Rebuilding it immaculately so no avail and get a badly slipping clutch in return.
A brief stop in leaking oil however. Defo oil!
So. Next stop was sort the clutch.
I suspected the master cylinder was not in great nik, so I pulled it apart and found all manner of badness. Crusty lime scale type deposits everywhere. Stuck circlip a etc....
So cleaned and made sure the relief hole was patent and rebuilt it.
Stuck it together and so far no clutch slip.
However I do now have a drop of oil again.
Now whilst looking around I noticed that new push rods are the same both ends. Mine is flat on one side and beveled on the other.
I asked about one on eBay re length. Mine is also shorter.
Could this be the reason oil is passing through and also why it doesn't disengage properly? Makes sense to me??
Opinions please?
Cheers all

[rooster]

3 stick of TNT and a short fuse

[robz]

Getting tempting haha