A Z900 challenge to the forum with a prize

[Thezedsintheshed]

Just had another thought , it could be possible that the ignition system is suffering from a gradual voltage drop due to a fault within the charging system or battery? If there is a fault or weakness in either the charging system or the battery then there will be a slow voltage drop in the system as you travel along , you say that the bike starts fine and that the fault gradually gets worse as you approach the 3 / 5 mile distance ? To check this rig up a volt meter across the coil feed which you say is 12.3 volts at rest , if you can rig the volt meter in place and then go out for a run and watch if the voltage supply to the coils to see if the voltage supply drops as the distance travelled increases and the fault becomes more obvious. Any gradual voltage drop in the system will in effect weaken the spark giving the impression of an over rich mixture because the spark is too weak to burn all of the fuel mix.
The ignition mod as suggested by Jeff Saunders is definatly worth doing and is relativly cheap to do, a new 4 pin relay is about 5 quid in Halfords but this mod will not cure any longterm underlaying problem that may be causing a voltage drop due to any charging system or battery fault.

All that said, I still think that the road legal baffle is a major factor that is making the problem more obvious, I have a spare Alfa 4 into 1 system here that I know works well and you are happy to pay the postage both ways then you are welcome to borrow it to rule out the exhaust system as cause of the problem.

[Phil50]

cheers
whats the postage for that?
Also I have original exhaust flanges but no collars. The harris just bolts on and has its own flanges. T be honest I think if I leave it runnig it will blacken the plugs but will try anyway.

Thanks for the hints
Phil

[Al]

Sorry its' a bit late i have just joined. Assuming all else fails this should be true for everyone with choke circuit fault if that's what it is.
Borrow yourself a bank of vacuum gauges. Test vacuum and adjust for carbs as per normal. Once satisfied, allow to idle and pull, in tiny stages; the choke lever and i dont mean two stages on clicks. Observe the effect of choke on vacuum and adjust claws where appropriate. If adjustment is available fine, if not replace choke parts as required. This will tell you everything you need to know about the choke circuit. If significant adjustment is needed to claws then you will have to re-visit the carb vacuum side again since the chokes will have been giving a false reading of the true vacuum of the carbs. Hope it's not too late as some time has elapsed since your original post.

P.S. you need to do this cold as well as hot!!! ie at least twice.

AL

[Phil50]

thanks for the advice.
I tried the new exhaust race baffle. A complete and utter waste of time (and money) as I was so advised by an exhaust manufacturer.
The carb chokes were tested and they are all working perfectly.
The ignition sysytem is also perfect and all voltages are correct.
another set of carbs were tried
It still runs rich.
Enough is enough
As I cannot find a qualified and competent Kawasaki mechanic anwhere within 100 miles who will take the job on. The bike is in storage till next year sometime when it will be broken down for spares. Or auctioned off
I would like to thank all who advised me on the various things to try. It was a mistake to try and recapture the dream.
regards and thanks to all posters
Phil

[Steve Cooke]

I don't think it was a mistake to have tried to recapture the dream, but I do understand how frustrated you must be.Anyway simple answer is to sell it to me for a price that reflects your contempt for it's 'unfixability' and you will then have a few bob to put towards a heap of shite like a Goldwing.

[simon gilling]

I agree, you were right to try and recapture the dream, I bought my current Z1 8 years ago, it has had a few electrical woes (35 year old connectors) but has stood up to regular use, trackdays and visits to the Isle of Man. Zs are still great fun to ride. From the posts I guess that you are down Harrow way, I am in the Midlands I would love to help you get it to run right. I have not failed on any of the non-runners I bought, yet... The garage is a bit full to make you an offer.

It may be nothing but..... in your original post you said you had it bored to 66.5 (916cc) and you fitted a Z1000 head, I don't know for sure but the Z1000 head may have a larger combustion chamber as the Z1000 cylinder displacement is larger and Z1000 has lower compression ratio than a Z9. Also the head would not match your cylinder bores which may effect the 'burn'. How was it running with the Z9 head?

Best of luck

PM me if you want to chat.

Simon

[Phil50]

thanks Simon
The problem was the same with the Z900 head. I swapped Heads because of a broken fin and the Z1000 has a more robust thread for the exhaust. I measured both heads witha digital vernier gauge. they are the same in size and fitting. I had sought advice on this from a person who rebuilds these things all the time and has never had a problem switching Z900 to Z1000 or vice versa.The overbore was 1/2mm so the size increas from 903 cc to 903.4 is negligible. I have had two offers already for stupid money like ?2000. I paid more for this thing and since then have had it rebored new rings/pistons cams valve guides rubbers gaskets ther lot. I would want ?3350 Cash so I could go out and get running bike something nice like a CB 250 G5 I used to like that one.

I think my mistake was trying to fix it myself and taking duff advice. I was desperate I spose. The real solution would be to just thow it in a garage that has trained Kawasaki Mechanics and plenty of older bike experience types and just pay up for a fix. I had offers of carbs to borrow but my emails were ignored. no suprise really. Who would want to borrow my carbs even for a day! LOL.

I also just got an email from and old friend who emigrated to New Zealand 20 years ago who also flogged off his recently aquired Z1A for scrap as he also could get no fix for a bike that simply would not run on 1 and 4 cylinder. Crazy? Well he spent $1000 and three months without result. So I am pleased it is not just me who is unable to get a Kawasaki Big Zed as they call it, running.
I do have a Revel airfix kit of one in the loft so I am going to glue that together over the xmas holidays. At least it wont run rich.
thanks mate
Phil

[Garn 1]

Phil, so who gets the prize?
Regardz

[rickman CRR]

Looks like we have all run out of ideas.

As a last gasp (sic) suggestion, are you sure you have the correct airfilter fitted for the airbox fitted to your bike. If you have an earlier Z1 airbox fitted, (which are more readily available than the later Z900 unit) and have fitted a Z900 A4 filter, it isnt going to get much air as the earlier airbox draws air from the top cover. The Z900 filters air drawn via the rear part of the box. Mix the two and it'll choke, run rich, splutter and die, just like you have described.

Maybe too simple, but perhaps worth a look?

[Pigford]

RUN WITHOUT FILTER, THAT'LL SEE IF ITS CARBS

[Phil50]

So kind Gents
WIth air filter without it no difference. Even took the entire airbox off still rich
Removed the air screws 4 turns. Still rich. Took needles to last slot. Still rich.

My Airbox is the standard KZ900 with a removable plastic lid to get at it. the only thing missing is the long muffler tube and that is only for soud and makes no difference to fuel consumption. Years ago I ran my Z1 without and without with no difference. I preferred the Sucking sound so left it of. Course today this entire bike Sucks!

I am considering removing the entire set of air screws and fitting main jets of 85 to see if that helps LOL!
thanks lads, you are all kind but this bike is unfixable and it has been tested/fixed by the best in here and still it wont run normal. It is just one of those things. Sometimes you have to know when to just walk away.

I have had some excellent suggestions from some knowledgable people and I am grateful. I had originally planned to save up many, many grands and just buy a running model from some one like classicbikes.co.uk But I got sucked in by a ruthless,heartless and dishonourable dealer and have been paying for it ever since.

My advice after this experience is NEVER buy a bike unless the RAC/AA or whoever have done a VERY thorough test. Unless you get it for peanuts.
regards
Phil

[paul doran]

are you one hundred percent sure that valve timing and shims are okay
a Zed with either of these faults will run but rich
don't give up
a Zed is for life not just for Christmas

[Pigford]

IGNITION PROBLEM, NOT ENOUGH POWER IN SPARK TO BURN THE FUEL
Bad earth, poor connection, etc, sounds favourite if still rich with air filter off & smaller jets
A good mate Percy Verance will always help

[paul doran]

go for it Mark

[rickman CRR]

C'mon guys, who lives near Phil, maybe it just needs someone else to look over his bike?