Z900 A4 fuel leak any ideas please?

[Gray17]

Ah ok Warren that makes sense, so are you saying you shouldnt double washer the float valve, as per Zpowers bulletin or bemd tab more to compensate.
My trouble is i have 2 workshop manuals a Haynes and the Kawasaki one both show the Z1 type carbs not the A4 later ones, even the suplememt doesn't show the A4 type carbs. I suspect they are more like the Z1000 then the old Z1 type be them very similar.
Its almost like the valve is either fully open or fully closed and the float doesn't control it very well, but only on that carb the others seem fine.
Ill keep at it

[warren3200gt]

Graham, you have one workshop manual and some toilet paper.
Flush the Enid Haynes Blyton copy.
Vm 26 carbs are the same as vm24 's bar the throat size in this area. Download a Z650 kawasaki manual for a better idea.
You don't need to double washer the valve seat. I assume you have genuine valve needles and not some dodgy after market ones. The aftermarket ones whem compared to genuine can vary in overall length and pin spring strength so there are no hard n fast for non genuine settings.
If they are genuine the float tang is normally around the metal thickness plus half again air gap bent up when viewed level with the main float plate. However It'll depend if the floats are actually bent up or down from where they should be on the main float plate.
It's a matter of making what you have work and thinking through what you need to do to make them work.
What you don't want is the tang bent at an angle big enough to stop the needle being lifted Straight in the valve.

[ADRIAN H]

Ah ok Warren that makes sense, so are you saying you shouldnt double washer the float valve, as per Zpowers bulletin or bemd tab more to compensate.
My trouble is i have 2 workshop manuals a Haynes and the Kawasaki one both show the Z1 type carbs not the A4 later ones, even the suplememt diesnt show the A4 type carbs. I suspect they are more like the Z1000 then the old Z1 type be them very similar.
Its almost like the valve is either fully open or fully closed and the float doesn't control it very well, but inly on that carb the others seem fine.
Ill keep at it

Haynes manuals on these bikes do not give correct information. Only use a Kawasaki service manual.

I’m pretty sure I have a PDF version of the Z900 kawasaki service manual. Let me have your email and I will Drop- send you a digital copy.

[Gray17]

Thanks Warren, as far as i know they are genuine valves and floats but in 40+years its possible these have been replaced previously, i havn't i merely replaced the o rings and gaskets when i stripped carbs, set up static height on the bench for all 4 carbs and did the same with the floats, least i thought i did? None of the float tangs are bent much at all inc the one thats causing the issues. Even when it runs it seems to be hesitating and it will tick over for a while and then cut out again, its when it cuts out the fuel starts leaking from the overflow again. It does now stop if you turn tap off eventually so new tap at least is shutting fuel off.
Have to say i have restored several motoring items over the years the last being a Suzuki GT750, none were as problematic as the Kawasaki, of course ive never owned a Z900 and always aspired to one. When i was younger they were always just out of my financial reach, by the time my apprenticeship finished and i was on decent money i was married so agsin fell by the wayside.
So 50 years later the opertunity presented itself i jumped at the chance (too quickly i think) as have spent a small fortune getting this one back to standard and rebuilding it, However I'm starting to loose patience as the nearer you get to actually riding it the more it seems to resist by way of more issues. You solve 1 and another crops up.
The Suzuki was a doddle by comparison. However im into it for a lot of money and determined to get it finished, surely cant be much more left to sort?
Adrian thanks for offer of manual, have sent you an email Cheers

[Bill P]

Stick with it the reward will be worth the hard work and sleepless night's

[ADRIAN H]

Adrian thanks for offer of manual, have sent you an email Cheers

I have sent a wetransfer link, with what I have. Good luck with sorting your carbs. I am working up the courage to sort out my Z1B carbs, which have been troublesome with overflowing float bowls.

[Gray17]

Yes got it thanks Adrian, hope you have more luck with your carbs then i have. To be fair the Suzuki i restored the carbs were pretty much spot on, so whilst cosmetically it looked rough, mechanically it was in reasonable shape, that said still needed crankshaft strip and new seals, not by me i hasten to add, had a local workshop split it replace seals and re balance it. Luckily Kawasaki didnt need that. But pretty much everything else. Its not like you can just pop it in to your local dealers as most arent familiar with fettling classics and most of the old timers have now retired.

[Gray17]

Morning guys, right new day renewed enthusiasm, not sure how long that will last though!
For some reason today no leaks from carbs which is strange in itself as was pouring out L/H carb last nt, however not going to look gift horse in mouth. Decided to start from scratch, removed each plug in turn all 4 sooty and black, so running rich, cleaned plugs all 4 original NGKs and spark well, re started bike fires up immediately but wont tick over unless over 1500 revs, doesnt respond to throttle well either, when you open it it hesitates then revs sore and slowly settle when released.
Im getting to the stage that this is now beyond me, firstly i dont have any of the correct tools, vacuum gauges, fuel level guage, strobe etc, and could be a lot of things causing the issue, so thinking is there anyone nearby ie Hull area that could help? I have no problem paying.
Mostvof the dealers near me deal with more modern machinery and not sure they would do my bike justice.
Thanks

[warren3200gt]

If you were closer mate or you don't have any volunteers close to you and you would find a courier to get it to Kent I'd happily help you out foc.
As its running it can only be settings assuming all the carb parts are original and in good nick.

[Gray17]

Thanks Warren, sure you would, wish i was closer too probably warmer down south and more scope.
My problem is the bike was an import it has been messed around with for 40+ years i dont know if any parts are original or pattern, it did run of a fashion but was unroad worthy when bought nor was it uk registered. So never been on UK roads to date.
I have set about restoring it back to original as best i can, however there are so many things it can be that you tend to go around in circles.
So far i have removed plugs all are black and sooty so very rich, cleaned them and re gapped them to 25, statically the spark looks to be in the right place but dont have a strobe to confirm or if advance and retard working ok. Although physically all looks ok and moves as it should, however its possible its got wrong springs on it, how would you know?
Bike starts but needs choke even tho running rich, when warm it wont tick over at anything less then 1500 rpm, when revved it seems to be holding back all time and revs dont drop off when throttle released seems to hang then drop.
Carbs have all been cleaned everything looked to be in good condition, new gaskets were used but no new jets etccarbs initially wernt getting fuel on 2 pots but think this was down to faulty tap, which has now been replaced, all 4 carbs have fuel in the bowls and bike runs on all 4, i have removed cap on each in Turncand this drops revs proving all 4 firing, also all 4 pipes now get hot 1 didnt before but think thats as it was starved of fuel, this seems to be ok and fual not pouring out overflow anymore.
I have tried adjusting mixture screws all way in then back out 1.25 to 1.5 turns, this hasmade it worst, hence going round in circles.
And my request for paid help, if i buy all the tools I'm not convinced ill be any better off as a tool is only as good as the person using it.
Perhaps someone close by can assist or suggest where to try?
Thanks

[warren3200gt]

Fingers crossed for you Graham, sure someone will step up, but if they don't the offer is open

[zed9]

As bike was a import and bit of a mess it could have been left standing for many years with dirt and old evoprated fuel blocking jets and airways. Have you removed all the jets to check them and blown airways out with compressed air and checked they are the correct sizes.
Are the air screws underneath carb or on the side?.

[Gray17]

Yes hopefully Warren fingers crossed.

Zed9: yes carbs fully stripped and cleaned all jets blown through with airline and clear, not sure about jet sizes assumed they were all ok as bike was running.
Screws are flat screwdriver slot on lower part of bowl side but you can undo them in situ. Def not underneath. If you mean mixture thats top side of L/H 2 and top side of R/H 2. There doesnt appear to be an air leak between carbs and head otherwise mixture would be weak.

Just had a thought when i got the bike it was fitted with a 4 into 1 exhaust which looks like a Delkevic. I have re fitted a 4 into 4 standard system provided by Zpower, however wouldnt have thought this would effect things that much? Think prev UkK importer just fitted it as it came without exhaust and looked new cant see him modding the jets

[Grog]

Hi Gray

Sorry you're still getting grief with this. Just looking through your last post - I assume the screws you mention on the lower bowl side are the drain screws? As long as there's no fuel passing there they won't make any difference to your problems. The air mixture screws - happy to be corrected but shouldn't there be one on each carb? On mine (Z1R) they are on the outer side of the carb body - I know some other models they are accessed from under the float bowls, but not sure which you have - especially as you say it has an unknown history.

A couple of other thoughts. You say it came with an aftermarket exhaust. Did it have pod filters or the standard airbox? There's a decent chance it's been given bigger jets and/or an air corrector kit which might be causing fuelling issues if you've swapped back to a standard setup.

Last thing - hanging revs. Normally two things to check. A) The throttle cables are correctly routed and adjusted, B) Lean running - though how it gets to there from being rich on idle I'm not sure, unless it's after transition from idle jet to main jet running.

Not sure if/how any of this helps, but might jog someone else's memory.

TTFN Grog

[Gray17]

Thanks for reply Grog, in answer to your questions yes sorry my bad description yes lower screws are carb drain screws.
Again my bad description each carb has its own air correction when i put 2 L/H , 2 R/H i meant you access them from that side but 1 on each carb, as per manual have screwed these fully home (not tight) then backed them out 1.5 turns also tried them all at 1.25 turns made no difference other thennow it wont run at all!
As for air filter it had the standard air filter still fitted, but without i believe its called the silencer circular tube part, but most A4s dont have this now. Very hard to get hold off and in my case cant be fitted due to larger battery.
Yes have to say after 18 months work, it looks lovely, so really dissapointed after all the work and money put into it, it refuses to run properly, I'm now at the stage I've done everything i can, i could continue to throw money at it but this still doesnt mean it will run correctly as have no idea what the issue is?, seems the more i tinker the worst it gets, hence my call for help if anyone lives nearby.