Z1OwnersClub GB

Hi
I have a KZ900 and thought what a lovely bike until I rode it and it choked to death.
I returned to the shop and two plugs were replaced. It was fine for three days.
A carb got broken by an incompetent trying to remove the jet needle. this wrote of the carbs. I got another set much cleaner and in excellent visual appearence. This time I myself replaced, the main jets to 115,the needle jets, the jet needle valve. The airscrews, the little fuel inlet valve under the floats and set the airsrew to 2 and 1/2 out as recomended rather than the 1 3/8 NO DIFFERENCE even after attempting to balance the carbs. Oh ,I set the jet needle to the centre position.

The exhaust is a street legal harris 4-1. The carbs are 26 mm Mikuni standards. The inlet rubbers were tested with easy start. No probe. When balancing I noticed that some fuel came out from the tubes. I also set the float lower. I am now unable to to drive more than 1 mile before it starts to die and it seems after 11 phone calls ( W.London area) No one will touch a Z900 with a barge pole. So if anyone can help please let me know or I shall be scrapping a nice bike for parts and going back to the car, whcih is 23 years old and works perectly! LOL Don't ask where I bought it as that is now a legal matter
thanks
Phil

Where exactly are you based Phil? as there is a good place in Reading.

Or Debbens at Ringwood.

Speak to Larry Webb at PDQ.
http://www.pdq1.co.uk/

Check tanks not choked with cr*p This may be fuel starvation

try Big CC at http://www.bigccracing.com/ based at

Big CC Racing
The Speed Shop
Fishponds Road
Wokingham
Berkshire
RG41 2QL
very handy with big zeds

A few helpful suggestions I am grateful. I am based in London so I cannot get the bike anywhere more than about 3 miles before it chokes up. Trust me it is not starved of fuel. It has too much fuel ))))

I spoke to a guy today who will test the carbs out for free on one of these Dynomometer gadgets. Also a friend in the USA told me that a compression reading of 80psi is BAD NEWS!!!. He expects 150 normal. Less than 100 he strips it down to test rings/valve carbon buildup, etc. This sounds familier to me as the pistons look black to me

So I have a few options. just don't have the money to fix it all right now.
Won't give up, will put ?500 more in to the project then perhaps it might catch fire )). Just kidding.
thanks all
Phil

If you get stuck try dogs bollox mikehunnisett@yahoo.co.uk located in near Ruislip in west london, he does my Zeds, by now he must be the the carb "know it all" maybe check this out first.

heres an edited version of his article on a choke problem

Before I start, I bought this Z1B as a non-runner from a mate who had left it standing for about 8 yrs, so I knew I was going to have a few problems. The carbs had been cleaned by Steve Smethurst, rebuilt with masses of NOS parts and I spent many hours cleaning & checking all the orifices?.. LOL

So if you have carb problems here?s a few things you need to check, some obvious but one certainly less so.

I grabbed my tatty copy of the original workshop manual & read-up on how these carbs work. So, when starting from cold you must not open the throttle, this defeats the object! My bike would only run, reluctantly, by feathering the throttle and then only on 3 cylinders? don?t they all!

Finding No.1( Image 1 + 2)
Armed with a little more knowledge I stripped my carbs AGAIN and examined the chokes, choke ports & brass atomizer pipe and low and behold uncovered my first problem NO CHOKE JET in the atomiser pipe No.3 carb.
The first image (all blurry I?m afraid no David Bailey) shows the end of the atomiser pipe in which there should be a small jet (~1/64? diameter hole) and you?ll notice that mine is completely missing.. The second image is for comparison & shows this small hole in carb No.4.
I now need one of my fitters at work to make me a jet.



Finding No.2 (image 3)
I now turned to the float bowls themselves to test whether the hole that the choke atomiser goes into was clear, was it ####!! I found 3 out of 4 blocked, so by using a Pin-chuck I cleaned out the vertical & 45? holes with a
1mm drill so now fuel can be drawn into the choke tube.

Finding No.3
Again with carb No.3, in the hemi chamber alongside the choke tube are two holes that run parallel with the axis of the slide, one is slightly bigger than the other, one of these was blocked at its deepest point. I used a lot of release agent, strands of thin copper wire and tons of patience and finally cleaned this out too.

Phil50 wrote:A few helpful suggestions I am grateful. I am based in London so I cannot get the bike anywhere more than about 3 miles before it chokes up. Trust me it is not starved of fuel. It has too much fuel ))))

I spoke to a guy today who will test the carbs out for free on one of these Dynomometer gadgets. Also a friend in the USA told me that a compression reading of 80psi is BAD NEWS!!!. He expects 150 normal. Less than 100 he strips it down to test rings/valve carbon buildup, etc. This sounds familier to me as the pistons look black to me

So I have a few options. just don't have the money to fix it all right now.
Won't give up, will put ?500 more in to the project then perhaps it might catch fire )). Just kidding.
thanks all
Phil

checking carbs as bedlow 1 said is good.i would do a top end strip overhaul,rebuild then you know its done right and the condition of everything.a zed is always worth spending money on.and the peace of mind knowing your engine.good luck

Is this a problem that has developed, or has it been like it since you've had the bike?

Compression of 80 psi is un-serviceable.

Did you remember to do the test with the throttle fully open?

I've made that mistake before and got myself in a right panic with readings of about 75 psi .

Realised what I'd done and re-tested with throttle wide open and everything was ok

Personally, I wouldn't strip the motor for the sake of it, I'd persue the fault finding first and only go inside if necessary.

Andy

The bike is now in a dealers and is going on a Dynomometer system. The guy came recommended and has owned 3 Z900's in his time.
I hope an answer by tomorrow Monday. He is testing the carbs first, and then decoking with some chemical to try and get compression up. If this works great. If not it wil be a head strip and full decoke and regrind valve seats. About ?275 all in. Not too bad. i don't have the time to do it so i am going to let him sort it out.
some useful replies, thanks. Wish I new about the Ruislip guy two weeks ago! Could have got there in 10 mins )))
regards
Phil

Hello ALL!
I have stripped the engine down. The vale oil seals are gone. Tha cam chain rollers all worn out. The piston rings are buggered as are the bores and it need a 0.5mm kit piston oversize at ?295.00. The coils have 2 broken leads as well. total cost to renew will be about ?850 with valve rescut and cleanup.

Had enough. its going in the shed and is for breaking next year. Unless I make some dosh with 7 weeks of summer left.
My advice to any buyer of these old Z's is simple go to Halfords adn buy a compression tester for ?18. Take this with you and test ALL 4 cyclinders before you part with ONE PENNY. The compression should be 145psi. Any cylinder showing less than 135PSI walk away quick, unless you have loads of time and money to repair it all.

I though that a little thing like choked up and running bad was carbs. It was not. It was Carbs and coils busted and rings and bore.

thanks for all the previousa advice I had on this board
regards
Phil

Phil sorry to hear of your misfortune, it can happen to any of us, but don't give up on the old girl. Coils aren't a major problem, loads of good used ones around or fit some dyna's. Likewise barrel and piston kits come up on e-bay all the time (until you want one) so be patient, the parts will turn up.
I know it is a pain when things go wrong, I don't even have the luxury of a garden/garage/shed, when things go wrong for me (and they do) I have to rebuild my bikes out on the street, and I do mean on the street. But I battle through, and my bikes mean more to me because of it, and the scary part is, I don't even buy runners, I drag home bikes that haven't or can't be started for many years.

thanks Kev

I am fitting a Boyer ignition with digital coils. As to pistons I am stuck with Zpower at ?295.00 a go. I need them this year and they are relibale parts )) I have a front garden and a tarp to work under LOL. I have got all the cam chain bits less one roller from ebay and that saved me ?260!!! So not too bad.

If you know where I can get new piston kit cheaper let me know.
regards
Phil