Z900 A4 fuel leak any ideas please? (semi solved)

[warren3200gt]

This explains it clearly Al. Follow the arrow directions although in our case it would be plug 1 & 4 and 2 & 3. I've had this conversation with Graham previously.

Screenshot_20231030_144959_Samsung Internet.jpg (48.57 KiB) Viewed 413 times

[Gray17]

Thats a great drawing Warren and shows the circuit clearly the only thing is as both leads are unmarked and same length how do you know which is which, ie 1 will be the + side the other the - side, guess try both or flip the pickup. To answer Als question yes the strobe has a pickup.
As for the airscrews I'm now confused as does backing them out allow more air in or more fuel? Nigel and others suggested increasing the pilot jet from 17.5 to 20 or even 22, so assume this allows more fuel in. As they are standard and think its running weak should i turn the screws tighter ie only 1 turn out rather then 1.5 turns.
As for timing i will try the static method as suggested using a bulb and wire see if i can get it to run again. What i cant understand is with the Zpower plate in place turn to 1 extremety on both plates , then the other extremety and the timing marks never moved or lined up on cylinders 1 and 4 or 2 and 3, yet they did on the old plate.
Something not quite right somehow.
In case i got it wrong on the cam swopped the blue and black leads around this just wouldnt start and backfired (which blew the rubber inlet cap off).

[warren3200gt]

OK, firstly the inductive strobe pick up. If it's on in the wrong direction for that ht lead you'll get an intermitant signal / flash.
The airscrews are on the side if the carb. Think of it as a tube which is partially blocked by the screw. Opening (turning a/c) reduces the blockage and allows more air through the tube. Screwing in (turning c/W) increases the blockage thus reducing the airflow. Less air =richer, more =leaner. The amount of fuel supplied doesn't change only the amount of air. Thus changing the total mixture leaner or richer.
However if you have fuel screws (under the bowl at the engine side) the opposite is true. Screwing in reduces the fuel flow making it leaner. Screwing out increases the fuel flow make ng it richer. On fuel screws the amount of air doesn't change only the amount of fuel thus making the total mixture richer or leaner.

[Gray17]

Thanks Warren that makes sense now, mine are the screws on the side rather then underneath so easy to access, if its running lean screws nead to be in more then , i turned them wrong way made it weaker no wonder it wouldnt run, will re try tomorrow and have a go at static timing. I would really like to sort out this slow running issue and get some rides under my belt, then take off the road September time and maybe strip motor down, my only concern is could i have cracked a ring, if so how much damage will it do if i run it? I dont do a lot of miles just a max of 150 a week but only when dry, which at moment isnt that often. If i strip it down now im going to loose it over the best part of summer. But could save the barrells, on the other hand i could strip it and be nothing wrong but general wear
Is there any way to know if a rings gone?
Its a real dilemma
Advice needed Please

[warren3200gt]

It depends where the ring has broken (if it has). If it's broken into 2 half's then it'll do little damage to the bore as it wouldnt be able to twist in the bore that much. If it's broken say 10 - 15 mm from the gap the broken piece would have more room to twist and would score the bore badly if that makes sense?
A leak down test would give a good indication assuming the valves are sealing well.
I doubt it has a broken ring. You'd have to be pretty ham-fisted to break a ring fitting the barrels on a Z. The lead in chamfer on the barrels is huge. Your more likely to break a ring when fitting them on the piston but you'd know you've done that.
I really think you should duplicate you compressions tests as the figures you posted earlier indicate either operator or equipment error.
Which cylinder was it that gave you the grief when fitting?

[gray]

I've just has a thought. Looking back in this thread , you said you had stripped the auto advancer unit and reassembled it , but noted ' the cam could fit either way" ( page 9 of this thread)
I think it can make a difference, otherwise why would Kawasaki put marks on it to facilitate reassembly in the " correct " position?
As we were discussing optimising things, and getting small things right before embarking on the big costly things, might be worth checking that its not assembled 180 degrees out. ( tho superficially it would appear not to matter)
there is a score in the inner face of the cam ( my index finger) and a single line on the timing marks backplate ( my pinkie) that is separate from the pairs of the timing marks for the points.
It'll mean disturbing the points again tho, sorry

[Gray17]

Hi Warren to be honest if you read my original post, think they all did, i really struggled as have very little in the way of nails and my fingers quite large, if i remember rightly think i did the centre 2 pistons 1st supporting them on 2 wooden blocks to stop them moving and lowering the barrells onto them entering 1 ring at a time alternate pistons, then doing same for outer 2, i think i pressed them in with a plastic spatula into the chamfer. Once all 4 in the engine turned over lovely and you could see the oil mark showing they were cleaning the bore of assembly oil i used. That said, somethings def not right on cylinder 3 this is the low one that has the timesert in plughole and seems to struggle for tester o ring to seal, but a bit of oil in bores and psi jumps on 3 of them 1 is already very good with or without oil.
I have re tested 6 times now 3 with oil 3 without bit all cold.
I have even tried with both the angle and straight attachements with rubber bung, result was worst. In all cases battery fully charged, throttle wide open, took 3 or 4 rotations to full reading.
Silly thing is no.4 is the one that smokes on start up but not black but clears when warm, no 3 is the low compression?
Conflicting????
Gray will re check that cam tomorrow, but think ive tried it both ways, i way it fires 2 and 3 the other 1 and 4. As its then 180 deg out. Ive still got to try static timing tomorrow too.
Really need to try to get it running right

[warren3200gt]

I doubt you've broken a ring and think your issues are either timing or carb settings or both.
Your comp tests are probably a red herring which are mainly down to sealing issues.
Static time it and set the airscrews at 1 & half turns out from seated and you'll no be too far out.
Report back after these.

[Gray17]

Yes will do 1.5 turns out was what it originally was set too, but the low speed running is crap. However i will do static timing as thats clearly an issue and worst with new plate in place which doesnt make sense.
I will report findings, just thinking what a prev post said that if bob weight springs wrong it will be starting to advance at too low revs so be wrong higher up rev range, will check that with strobe make sure it only advances after 2k
Thanks
Update alas not had a great day! Started off removing points plate again and re checking cam, it was in the correct way, so re fitted that and replaced points plate centralising the plate, then re set the points on both to 0.4mm, next with the bulb and 2 wires 1 on points wire other on earth and tried to set up static, no matter what i did with plate it would not line up with F mark at all. Theres something wrong or I'm missing something (probably me), may try re fitting original points plate but it looks identical with grummet coming off at bottom just like original and 2 sets of adjustments. If its not lining up properly then no wonder it wont run right. Thought timing would be simple, after all on a car you start it up shine strobe on marks and turn distributer back or forth till it lines up assumed bike the same but now thinking when i did that on mine it actually ran worst.
Just not having much luck at all at moment!
Try again tomorrow

[Gray17]

Hi Guys well removed timing cam plate as Gray suggested checked
For marks as per photo (Is this advancer the correct part for Z900 A4?), nothing on mine at all there is a dot but nothing to line it with on cam, the cam is free to fit in either position which is strange, however as i have no idea if any parts have been prev replaced no way to know (see photo), anyway re assembled back again, 1 thing i did notice the long shouldered bolt which holds the cam in place is very slightly out of true, checked it by spinning slowly in a drill, however when in place and tightened up doesnt allow any movement of the cam itself so may well be another red herring, also noticed new cam plate can move slightly on the 3 fixing screws not when tightened but you can move up and down 1/2 a mm or so on the screws, therefore may not be perfectly central?,clutching at straws really. My friend came down yesterday and told him still having probs, started bike up, he said straight away its running too rich you can smell it and its choking itself, mmm thats interesting as everyone seems to think its running weak, removed plugs yet again sure enough black and wet so def running rich, however it only wants to rev at low revs on choke, back choke off it refuses to rev which is the reverse of what you would expect.
Going to replace cam and re try to static time again. Didnt have much success yesterday at all.

UPDATE TODAY
Been at it all day trying to time up statically, tried it with a meter, a bulb and even a buzzer, it just point blank refuses to time. Its almost as though you can see the points open but the other points set seems to keep bulb or buzzer on, could it be the capacitors at fault?
I have made sure none of the wires are shorting to ground, theres def 12v on the points and the neg is connected to earth, if i flick the points you get a small spark and plugs spark what am i doing wrong?
Please help before i commit suicide!!!!
FURTHER UPDATE
Thanks to Warren managed to determine what i was doing wrong i was clamping bulb/buzzer to point where wires are attached to points , for some reason this was causing a short, Warren suggested clamping to the points spring metal which worked, however it still refuses to align with the marks at point of opening, its almost as though its too far retarded, no matter which way i move the plates with the slots fully forward or backward it still wont line up, even tried moving the backung plate on the 3 screws fully forward then backward but still not in line. The points gap has been set to 0.4mm on both sets. The bike will start and if i run it with the strobe it advances at 2k revs, however with it ticking over the alunement mark is passed the no.4 mark nearer to the advancer pivot then the correct mark between the 1 and 4.
I did notice when i stripped the advancer down it was sticking slightly socleaned everything and re lubed with bit of oil, all nice and smooth now, but still not lining up. This is the same with both the original points plate and the brand new Zpower one also. Hence why i asked is the photo of my advancer correct for my A4 model or has it been replaced with wrong part? Theres something def wrong, 1 suggestion was to elongate the plate holes longer but looking how far its out id need to file half the plate away. Also if i file or drill it on the wrong arc the points plate will move and not be central. Theres got to be something wrong somewhere, perhaps with my assembly or possibly wrong advancer assembly fitted at some point in its past?
Also if i start it up let it warm off choke then try revving and holding at 4k you can hear it missing every so often and you get smoke from exhausts but not black more like rich smoke. When i rode it there was no smoke behind or when on overun or changing down. Its already had new exhaust valves, guides and all new stem seals too
Suggestions welcome please as im running out of ideas.

Thanks

[Gray17]

Been at it again today, spoke at length with Warren re lineing up the points, mine just refuses point blank to line up as it should, Firstly set the points gap at 0.4mm, then bulb across Earth and the points spring part, turn engine over using spanner, if i set the left hand set ie 1 and 4 i can get it nearly on the F mark and the light operating but then the 2 and 3 are wrong no matter what extremety i move the plate to using the slot. I know they need to be 180 deg apart at the heel.
If i then use the timing lamp on plug 1 lead and get that lined up as near as i can then 2 and 3 are miles out. Again using the full lots extremety. I thought the issue may be the auto advancer but Warren says its the correct one for my A4, then i thought maybe the original points plate was wrong, ordered new one from Zpower thats the same too. I do everything as i think i should but it doesnt line up?
What is going on? Come on guys really need some help here.
Thanks

[Al]

The advance unit centre bolt is bent. Is that because its been down on the RHS. If so is the shaft that carries the advancer cam bent also?

When you run it and view from the side is the bolt or more particularly the cam, spinning eccentrically? A felt tip dot on the end of the bolt may help to see if it is.

Does it have the standard solid / hardened peg in the end of the crank that drives the advance unit? If not has it been replaced with something else?

Do you have the two 'soft dampers' on the bob weights of the advance unit as shown below. They are prone to falling off and this makes the retarded position for static timing incorrect!

AL

[Gray17]

Hi Al thanks for reply in answer to your Qs yes peg in crankshaft is original and looks to be not bent, yes the advancer has the 2 what look like magnets on the weights still intact. To be honest if you look at my photo it looks in a lot better condition then the 1 in your photo. But mine has 005 stamped whereas yours has 1020 not sure if these mean anything?
The central bolt is bent but only very, very slight as for the cam plate that looks pretty central and straight to be fair and doesnt move when the central bolt is tightened. Think even if it did it wouldnt be enough to account for the amount its out, but thats a guess. The engine case outer looks to be original but have no way to know if its been replaced, but after 40+ years anythings possible inc a dropped bike. There is no wear on the inner case or leak from oil seal so thats def not bent. Its strange, i wondered if the cam itself has worn? But Warren thinks not, its strange indeed. The zpower pattern points plate has made matters worst in this respect, so may put original back in, also looking at point less ignition as an option.
Thanks

[zapo]

Just forgetting the timing issue for a moment, check on the new points plate and check that the very small nuts holding the wires to the points are tight. I brought one of those zpower plates and the nut on the right was loose causing dodgy running.
Once tightened all was well but in fact, in my case a condenser soon failed as well and I had to swap them for the ones on my original plate - has run perfect since then.
Cheers

[Gray17]

Thanks thats a valid point, but not in my case they were both tight, wish it had been that would have been an easy fix!