Z1-R engine rebuild

[HowieD]

Aye up,
the time has come after 30 years of owner ship and f@%& knows how many miles to do an overhaul.

Just thinking of replacing the cam chain and the rubber bits that go with
the idler wheels and stuff.
Considering that the Main Bearing & Barrel Studs were adequate all those years ago is there any real reason, do you experts out there think, to replace them with some of those highly sexyfull items on the Debben web site? I was thinking of putting uprated idler wheels too ?

What do your think and is there anything else I should replace/uprate while its apart? That Clutch pusher looks nice too!

Not sure about a rebore either as when I had a look inside the bores there didn't seem to be any scoring and that last time I tested it the Compression was good.

Any advice welcome!

Hx

[RALPHARAMA]

My view would be that if it has survived thirty years and lotz of miles, why change a winning formula?

[ollie]

howie installing heavy duty idlers will make your engine a lot noisier mate,like ralph said why change if its ok ,unless its stuffed i would leave it as it is ,also if you change the cam chain ,i would advise using a genuine chain as the heavy duty, again are a bit more noisy and have squareish edges as opposed to the rounded ones on the genuine jobby,the heavy duty ones tend to wear the rubber parts down at a quicker rate .
unless of course you are building a big bore engine ,and need stronger parts .
I expect a lot of folk won't agree with me but this was my experience ,so i thought it may be worth mentioning

ps: debben is a good guy though, and he will be the best for advice


ollie

[HowieD]

Hummmm

Food for thought there.

Thanks for the replies.

Hx

[Rich]

As Ollie says Liska rollers will be noisier but more accurate and last longer if you are going for cams / HD springs etc. Barrel studs are good for high comp pistons.
If you intend to keep it std use Kawa rollers with the rubber bush, but check your original ones as the bushes go hard. Personally after 30k AND 30 years I'd replace all the cam rollers and chain while the engine is in bits.
With the exchange rate as it is check out Z1 Enterprises

[HowieD]

Well I'm at a bit of a loss now!

I got the engine out and all sturdily supported - took the Cam cover off expecting a corroded nightmare.

But it looks perfect! And along with the results when I had it boroscoped & the Compression test last year it looks to me that stripping it down might be a waste of time.

Looks a bit manky on the outside but I have a big BIG bottle of Cetem Ali-Clean for the furr. Will the Ali-Clean damage the Head Studs in any way?

So the question remaining for the path forward is: how long will a Cam Chain last? its the origional and done about 35K miles.

What do you recon?

Regards
Howie

[Steve Cooke]

35k is a lot of work for the original camchain, Kawasaki recommend replacement after a little over 2mm of stretch measured over twenty links, i'm sure yours will be in excess of that, and as Rich has said the original idlers with the rubber bush harden over time to a brittle plastic which will fail, it's not always a case of 'if it's not broke don't fix it' if it does go the damage can be major, is it worth it.

[HowieD]

Thanks Steve,
the voice of reason is what I needed really. Replacing everything will make it outlast me prolly LOL

AND stripping it down will allow an easier clean up of the cases.

Ta muchly

Howie

[Steve R]

Thats interesting Steve, how do you measure that lay the cam chain on something flat and push it together , mark 20 links then stretch and mark again? Presumably you can measure it with just the barrells off if its over only 20 links?

[Steve Cooke]

Steve you have to pull the chain taut with a tension of about 5kg then measure, the figures for an A1 which I presume will be the same on the Z1R or would at least be very similar are:-
standard length over twenty links = 155.48 - 155.71mm
and the service limit given is 157.8mm

[HowieD]

Is there any way you could gauge the stretch by measureing how much the Tensioner piston is exposed?

[RALPHARAMA]

Soz Howie, the only way to measure, accurately the stretch is as described above.

If you've got the facilities and knowledge stripping Zed engines is fun

You could use a link splitter, which would mean you don't have to split the casings, but it's not quite as good a job and not as fun, but can be done in the frame. Assuming she's not rattling or showing any bad signs, I'd leave her alone 'til the winter and then give her a total strip and rebuild, you could get the frame powder coated while you're at it, the original paint was awful, though I'll be shot down for saying it, as it's original now

[Steve R]

Thanks Steve will have a look at that tomorrow.

[Rich]

and while you've got it to bits check the guides and valves, the valves may just need lapping.
Think positive they're actually a piece of piss compared to a old British bike engine to put back together.

[ted1r]

HI IF YOU HAVENT ALREADY GOT ONE I HAVE A GENUINE KAWASAKI WORK SHOP MANUAL FOR THE ZI/ZIR AN I`M ONLY AT CLEETHORPES IF YOU WANT TO BORROW IT


CHEERS TED1R