Z1OwnersClub GB

I'm restoring a '73 USA spec Z1. When I first got the bike running it seemed as if it was running lean and would also bog and wouldn't accelerate or run even half way decently without the choke on.

Work done so far:
New points and condensers on a new backing plate.
New spark plug caps and plugs.
New camchain and guides
New valve stem seals
Lapped valves
New valve shims.
New cylinder head gasket and O ring
New fuel hoses.
New air filter OEM
New carburettor holders.
Carburettors removed and cleaned. Rebuilt using the correct kits. Used Kawasaki Needle Jet Holders, Needles 5j9's and Jets.
Fresh oil and filter.
The petrol tank has been cleaned of rust and sealed professionally.
New high flow Pingel petcock fitted

With the head off the bores were inspected and they are sweet, still with the honing marks on them.

The carbs were then balanced and the timing set. When I test rode the bike it was running only about 10 percent better that it had originally.

The mechanic then fiddled a lot with the height of the needles and timing etc. No improvement was able to be made.

Then it was discovered that there was only 8 volts going to the coils. I then took the bike to a well respected auto electrician who claimed that the coils were in fact getting 14 volts and that the timing on the bike was out and he had re-set it?

Attempting to test ride it again it immediately blew the fuse, twice.

The question is...What's wrong with the bike?????????????

Could it be faulty spark plug leads? The rubber carb manifold doesn't leak and it's nice and soft and unobstructed. The seat isn't obstructing the breathing. A symptom is that it soots up the plugs and one of them has a sticky residue on it which I think is from petrol I'm sure it isn't oil.

This bike had been sitting in storage for about 20 years I think.
I took a good cup of water out of the rusted up petrol tank along with the rotten gas.
And the condition of the engine is probably why it was just parked up. As a side note, the vendor on eBay USA advertised the bike as "It has a strong 903cc motor and the transmission shifts great". No mention that it was a non runner and basically a bit of a basket case.

Any input will be greatly appreciated. Thanks

Could be a shagged battery

Sorry, I forgot to add that I have fitted a new battery as well. Thanks, you were right onto it though.

The Japanese K and L Jet Needles that came with the kits were fitted and the bike ran like crap. I had sourced a set of 5j9's off Pigford but there was no improvement when those were used..

What plugs are you running. If you're running NGKs then skip 'em and use Denso's. For some reason modern NGK plugs don't seem to work so well on our classic bikes.

Do you know anyone with a zed who could lend you a set of coils just to rule them out if you've already read about the pain of NGKs.

The guy who set the timing; did he set it statically or dynamically?

is it possible that the 'new' condensers had been on the shelf a while? If it was my bike I would stick on a Dyna S ignition system, which only you will know is there and rules out all the PITA faults that occur with traditional points setups. Kawasaki only used points on Zeds cos they hadn't invented reliable, cheap CDI/electronic ignition

From your description it certainly sounds like an ignition issue

Hi, I read about Denso IW24's so I fitted those. They were sooting up so the mechanic didn't want to stuff them so fitted correct NGK's.

I have a guy in our club who has a Z1B so I might ask him to come around. Good idea.

I'm happy enough with old style points. I have them on my H**** and they don't give me any grief. Having said that, I agree with you that it could be ignition. Crappy spark leaving unburned hydrocarbons to foul the plugs and the unburned fuel washing the cylinder walls?? But why?

toycollector10 wrote: As a side note, the vendor on eBay USA advertised the bike as "It has a strong 903cc motor and the transmission shifts great". No mention that it was a non runner and basically a bit of a basket case.

Bythis time I would have thought you'd have got over getting pissed off about what the vendor said about the bike and being surprised at the inaccurate bits - what surprises me is that it actually is what he claimed it was and not a Z200 or something in a fat suit.
With this kind of running problem it can be painfully hard to tell if it's fuel or ignition related - or something else entirely - as almost all Zed problems worse than a certain point end up giving you the same type of shit running, but looking on the bright side I'd say you've done most of the hard stuff! You've had the head off and if it all looked good then all the usual valve sticking worn bore issues you could suspect with an engine that's been laid up for an unknown period, and with all the carb work you've had done, a cleaned tank and a new tap chances are it's not fuel. (Only proviso is that with an old tank it's always a good idea to put a clear inline filter in that will let you see any build up of residual shit trying to get down into the carbs after you thought it had all gone away to lead you up a blind alley for another week but that's by the way and maybe you did that...)
You're talking about sooted up plugs - rather than "wet" which one might expect - and you don't say if it's them all or mainly two, but on the balance of what you're saying and what's been looked already at it seems there are a few electrical areas still worth exploring. While a Dyna is undoubtedly a better idea there's no reason why it shouldn't go well enough on properly set up points so just banging a Dyna on is unlikely to effect a miracle cure it's just a couple of less areas to worry about. Coils and leads have to be a suspect as thirty year old leads are definitely not as good as new ones and the old coils easily can go too - there's a testing procedure in the workshop manual - but if it's all four cylinders they'd both need to be equally fucked (which is possible of course). If it's established that they definitely are okay (and okay is as far as I'd go it's unlikely they're really good) then how thoroughly have you gone through the loom for good wires and connections? Regulator/rectifier? It shouldn't be blowing fuses. More about this area in the workshop manual.These are what I'd look at next

I have no experience of the Denso IW24 and have no idea of what an iridium plug can or cannot do in a 70s engine or with points and a flaky electrical system especially if voltage is an issue (although I believe Pigford has used these but probably with electronic ignition). They may be all round better under any circumstances or they may require more voltage than a more traditional type plug and make poor running worse- I'm sure Rich has a view on this. If the bike is running and starting properly it will fine run on NGKs. If it's not starting well it may easily kill NGKs further confusing the issue unless you have a big free box of them so you can keep chucking new ones in it. I would take issue with the the phrase "correct NGKs" and all it implies as the bike's original NGK plugs were Japanese not Chinese copies and as far as I know Denso W24ES-U were always listed in the factory manual alongside NGKs as an OE plug, are still Japanese, and don't give up at the first sign of a fight.

This kind of thing requires a lot of headscratching and can take weeks to trace but that's the bad news - the good news is you seem to be most of the way there.


Although it's always hard to tell from this distance...

make sure the bike is not overcharging.it will give your coils a headache and cause all sorts of running troubles including flat spot.

Toy,
I gotta ask. Have you done a compression and a leak down test since bolting the head down. I'm not a tuning guru, but I had a similar problem with a bike that sat for a long time. Could be a compression problem. Just a thought as all else hasn't fixed it
Also a new head gasket and "O" ring KP

Hi Kerry. The mechanic did a compression test after he put the head back on with the new O ring around the cam tunnel and there is a new head gasket. It all checked out fine.

I'm sure that my H**** coils will fit the Zed so I'm going to try that and see what happens. Someone at work feels sure it has to be the coils and or HT leads that are at fault.

The problem for me now is that it's ramping up to Christmas time, I'm a shift worker doing some inconvenient hours and I haven't made up my usual "list of things to do and buy". So I'm feeling pressured on all sides at the moment. Too much to do and not enough time.

Wait, I hear a miniature violin..........

Thank you everyone for your inputs. Thanks Hondaman from the SOHC4 forum too.

toycollector10 wrote:Thanks Hondaman from the SOHC4 forum too.

And well done to Toy boy for working out how to beat the H**** filter

HONDAHONDAHONDAHONDAHONDAHONDAHONDAHONDAHONDAHONDA

I wonder if HQNDA works? Yes it does. Can I get myself banned from this forum for transgressing the unwritten rule?

Someone told me I had an anti-authoritarian streak in me and I can spell it, I think, but I'm not sure if I know what it means.

It's not big and certainly not clever

Toy. That rules out the compression test then but you might consider a leak down test as this can show up some issues.
Only other thing is the "O" ring as the 73 Z1 didn't have an "O" ring groove in the cylinder (as I understand) so would seem the cylinder may have been swapped. Maybe others can clarify this.
Anyway, leave it until after Chrissey. KP

The bores are in good condition with no scoring and the valves have been lapped in. A broken ring would surely show up and the engine runs like crap on all four cylinders. But it's still a good idea and I will run with it if the replacement coils and leads don't fix the problem. Thanks for your input Kerry..

Hi Toycollector

take a look at this link it may be of help

http://www.wgcarbs.com/index.php?option ... &Itemid=26

It has already been posted on here a few times in other threads.

assuming that everything working correctly on the mechanical side of things ie compression , valve clearences etc then the problem may well be down to a voltage drop at the coils , following the instructions in the above link should rule this out
cheers
Phil