Z900 A4 fuel leak any ideas please?

[Grog]

Hello mate; just catching up on this thread. Looks like you’re getting lots of good advice here, and as r3sc said, really hoping you can get this sorted and spend summer (when it eventually arrives!) getting some miles in.

Not much to add to all that’s been said tech-wise, but from what you’ve written about the bike being sluggish at low revs and OK higher up I’d still be leaning towards a carb/ignition issue rather than a problem with the cam timing – although you’ll obviously be wanting everything spot on in that department anyway.

For the carb sync, it’s the locknut/screw adjuster on the top of the carbs you need to get at, so yes – the top covers need to come off. Am I right in thinking that someone sent you the Kawasaki workshop manual? If so, everything you need is in section B (Adjustment – engine) in the carb section.

As to making things worse – don’t worry about that, if all else fails go back to your start point and work through it again. I’m strictly amateur at this and have spent more years than I can remember adjusting and fettling – and I haven’t killed either myself or the bike (yet)! Stick at it – it’ll be worth it in the end!

TTFN Grog

[ADRIAN H]

Should be done without cam cover gasket on.

[sean_rfi]

Hello Graham,
I balanced my carbs last weekend. It was a little more difficult than I anticipated as every time I adjusted one carb it had some effect on the others.
The one main thing I found was that when I had them all nicely synchronised tightening up the lock screw changed the setting so adapted my technique to compensate for this.

[Gray17]

Thanks Guys, Grog thanks for encouragement i need it!
Adrian yes was aware just lifted gasket up to check position.
Sean where did you get your gauges from or have you had them for a while? I bought a cheapish set off ebay thinking not too worried about accuracy as long as there all the same, they arrived, zeroed them all at atmospheric pressure, started bike and let it warm up with new Denso plugs in place, got it ticking over off choke, then stopped and fitted gauges 1 to each inlet take off, there was a bit of fuel in the rubber bungs, think I've read thats normal? Anyway started up bike gauge needles were flicking around wildly on all 4, completely unreadable or indeed useable. I know they weren't dear but they have to be fit for purpose these def aren't.
Hope i have more luck withe strobe light i also bought!!!!

[Grog]

Hi Graham;

Re. your problem with flickering needles on your gauges - did your set come with a set of damper valves? They look like T-pieces but have a small wheel on them. They fit in-line on each of the lines between the carb and your gauges (you will have to cut the lines at a suitable point to fit them in). If you look on Amazon for 'motorcycle carb synchroniser' it'll pop up loads of examples with pics for a better idea. They basically restrict the airflow through the lines (by winding the wheel in or out) and reduce the flutter to a readable level.

If you haven't got them with your set, you can achieve the same result by using small clamps - even clothes pegs can work, although they are a bit awkward to get the right amount of 'squeeze' on the line. Hope you get something sorted for them.

TTFN Grog

[Gray17]

Hi Grog good info, wasnt aware of that, the ones ive seen before in workshop didnt flicker at all guess their much better quality.
Theres no instructions with these just 4 x brass ext pipes, 4 x rubber hoses and yes 4 taps wasnt sure what they were for, will give them a try tomorrow but dont hold much hope to be honest.

[sean_rfi]

Hello Graham, as Grog has stated you have to use the gauge valves to restrict airflow, i.e damp the needle movement. It is important though that the needles still flicker a little to get an accurate response/reading - don't overdo the airflow restriction. Ideally the readings should be within approx 2cm Hg of each other. Make sure the engine is up to temperature and blip the throttle between adjustments
I used a carbtune meter that uses metal rods in clear tubes rather than conventional gauges. Same principle but uses small sections of microbore tube to restrict airflow.

[Grog]

Graham;

Attached are pics of the relevant section from the workshop manual for carb syncing. The pics also show you where the damper valves go. Ignore the brass pipes that came with the kit, you don't need them. Cut the rubber pipes that you have a shortish distance from one end. Attach the short bit - one end on the gauges, the other on the damper valve. Then the long pieces you have left attach from the dampers to the carbs. You'll be good to go then. As sean said, you need a bit of needle flutter (see instructions from the pics) but the dampers will make it manageable.

TTFN Grog

[warren3200gt]

Graham, we spoke about the needle dampers when you called me yesterday

[Gray17]

Afternoon Guys, well armed with all your advice decided to try again with vac gauges. Firstly used the 4 air restrictor valves in each rubber hose. New Denso plugs in place gapped to 28 thou, points cleaned up and gapoed too.
Started bike up and warmed, then stopped and connected gauges, started bike again on a fast tickover about 1500 rpm. Gauges jumping wildly still shut all 4 air restrictors nearly off still no use, they do stop moving as much but they are all over the place, never settle in same position. Think they're stuffed. Give up with them, emailed ebay seller, await reply. Re fitted 4 rubber caps.
Next started bike and took off 1 plug in turn using insulated pliars each had the effe t of dropping revs so know each firing ok, next trued adjusting air screw on carbs, tried turning in and out no effect on revs up or down, but if you fully screw in bike cuts out, so def working.
Next with my new strobe set up on plug 1 connected to battery, started bike at tickover 1000 rpm pulled trigger, marks no where near F mark it was just past the 4 mark, when revved it advanced and when released re settled to same position so advance seems ok.
Stopped and loosened all screws on face plate, re started and tried to adjust using points plate no matter whoch way i turned couldnt get it near F mark. So slackened off full playe screws (3) it was centralised before found i had to move to its extreme, then move contact plate to extreme to get F to line up, but wow what a difference it made, bike now picks up quickly on throttle and settles quickly too, revs seem much more responsive to throttle.
Stopped and swopped to cylinder 2, checked that which was again spot on to F mark, blipped throttlee and watched it advance then re settle tightened all up.
I removed all 4 plugs and checked colour all choccy brown which seems good. Its raining here so will tske it out for a spin tomorrow if dry, but def improvement thats for sure but wont know fully until ridden.
1 thing i did notice when you first start it up you do get a bit of smoke but clears when warm, you only notice if garage door closed, when its open in daylight you cannot see smoke, nor when revved, hoping thats not an issue. Maybe new rings bedding in.

[warren3200gt]

When starting on choke the mixture is highly rich so some smoke is likely. Black smoke is oil burn. Blue/grey smoke is rich mixture.
White smoke is condensation from water vapour burning off.
What colour are you getting Graham and when?

[Gray17]

Hi Warren, right def some condensation there as you get a few damp patches under exhaust drain holes, but believe thats normal, and does clear when warmed up, smoke is not black more grey again seems toclear once warm. When i took it out last weekend i was watching in mirrors nothing smoke wise, even on overun or downshift. Plugs are blackish on start up, but turns to brown once run a while which seems good to me?
Its more when its been stood, almost like oil draining into cylinders after stood a week, but its had new valve guides ex valves and stem seals, also new rings but not rebore. Its done 20k if you believe the speedo but it original so could well be true.
Oh and bought a complete points plate from Zpower inc 2 sets points, condensors and wiring just in case, i know its pattern but knowing their quality should be good and got a good deal too

[r3sc]

You’re getting there! Good job on the points plate!

[Gray17]

Afternoon Guys, well after yesterdays successes thought id finally cracked it as the ignition timing was way off, and in the garage it responded so much better to the throttle.
As they say todays another day! Decided to take out for a run as weather was dry, 50 miles each way to Thronton le dale and back via the biker cafe for lunch. Well very dissapointed, bike started well 1st press of button on choke, after a min or so backed it off to half and it would rev but not well,but would tick over another 30 secs of choke then set off, straight away could tell it wasn't right, but wasnt fully warm so perseveered. Slow speed was horrendous just wouldnt pull at all, even revving to 3k and releasing clutch slowly it just bogged down. However once on the move mid throttle upwards pulled really well all the way to 7k as far as i took it. Its almost a liability as it will rev but as soon as its put under load it just dies. The whole trip it didnt improve. At 60 mph it wasnt bad but at 30 it was terrible, you cant ride everywhere at 60 not with our traffic and limits it needs to be able to do slow reliably. Its almost like its missing or only firing on 3 but comes on song at higher revs.
So when got back home took plugs out, 1 and 4 black ish but centre electrode brown, centre plugs 1 looked ok nice brown, the other brown with white tinge so think that cylinder running weak.
Another thing 1 noticed the rubber blank plugs on inlet 1 had blown off in garage when revving, put it back on, got home after run and its missing, its blown off again question is why as youd expect the inlet to suck rather then blow! It also wasnt the 1 that was running weak.
Ive got 1 thing left to try, the new points plate inc points, condensors and wiring arrived from Zpower so will fit that re check timing with strobe and then try again in the hope it improves matters.
If not then I'm out of ideas and money too.
I am grateful for the helpful info and comments cheers

[gray]

is the cam timing a tooth out? If the inlet valve was still a bit open as the piston was rising, then you'd get increased inlet tract pressure and it might blow the bungs out.
Easy to get it wrong, and the diagrams aren't that clear in the manual - the thing to remember is that ( with No 1 piston at TDC and the cam cover off) the exhaust cam arrow should be flat to the joint face and this points to PIN ZERO, not pin 1 and you count from there to the inlet cam pin. It'll run , but poorly, 1 tooth out.