Z1OwnersClub GB

Guys,
As stated in an earlier post, my engine hasn't turned for 15 years. I now have it on the bench ready to strip the top end to check for moisture ingress in the bores, fit new valve seals, and hopefully just fit new piston rings. Engine has only done 10K from new, but if bores are corroded I might have to step up to the next size. What is the preffered choice of pistons and rings on here please? Whichever ones are best, a good supplier name would also be appreciated. Do you think I should change the rubber components in the cam chain adjuster mechanism whilst I'm in there?
Cheers in advance
Col

With only 10K on the motor you should be able to just hone/glazebust the bores for the new rings.
If you are very unlucky and there is deep pitting of the bores then Wiseco pistons are the way to go as many here will agree but if just re-ringing then original kawasaki is your best choice.
Rubber components might be ok , You won't really know until it's apart but there shouldn't be much wear on them.

Cheers,
That's all I'm hoping I have to do with the bores.

The J1 had a reputation for using a lot of oil. The fix or one of them was to fit J3 pistons (first oversize) and this apparently cured it. Didnt help mine as the previous owner found out.
Four or five years ago when i got to sorting this out there were no J piston rings available in first oversize available anywhere i was told.
I ended up reboring to 1170 with a set of gpz barrels and using wiseco pistons form Gremlin Racetec or Debbens.

Have a look at the crowns and skirts of the pistons that come out. If there are heavy carbon deposits (wet looking rather than dry scaley flakes) then chances are it was using oil. This needs to be seen in conjunction with the blowby on the skirts around the ring grooves and the deposits in the exhaust ports etc. Not a very exact science but it may give some indication particularly uniformity across the four pots.

I would replace the little damper block on the bottom of the cam chain tensioner blade (looks like a liquorice allsort) because they compress badly, and for peace of mind put a split cam chain on it while i was there.
Like as not there will be other issues to adress; possibly cam cap threads and bolts needing attention or replacement.
Take a really close look at the cam cap bolts with a magnifying glass!!!!
A one piece head gasket seems preferable too although you can get good results with the original setup.
Ape valve stem seals look like a good option but there are other choices here too.
AL

Thanks Al,
Yes, I am aware that the J's loved oil, although to be fair mine was never too bad so I assumed that a production fix had been in put in place before mine was built. Boring the liners BEFORE shrinking them into the block must rank as one of Kawasakis most cock eyed engineering practice's to date (unless others know of a better one). I intend to check for bore ovality with a bore guage, although I don't know how I will determine if it is within any service limit or not. Didn't know about the 1st oversize ring drought either, I'll worry about that when I get to that point. Cleaning the external crap off the motor at the moment in readiness for opening it up. Can I assume you are saying to check the cam cap bolts for fatigue cracks?
Lastly, why would you change the cam chain after 10K, I'm not knocking your suggestion, it's just something that I'd not considered that's all.
Cheers,
Col

The J ringsets came from ; 2 sets Kawasaki in Belgium, 1 set from Italy and one from some other third world country.

£200 for 4 in total and waited ages, hone, gaskets, stem seals, time spent doing it and didnt bother to replace the cam chain because by that time i was up to my neck in it or so i thought.

It didnt solve the problems of oil useage and worse, the cam chain had run out of adjustment when i put it back together.
I hadnt been focusing on the peripheral issues just transfixed by the appaling oil loss.

There is a dimension for the cam chain adjuster mechanism.
You have to measure it by eye and from memory its something like 5mm of the rod left protruding from the threaded portion of the body.

I replaced the cam chain later but wished that i didnt have to but by then it was immaterial because it needed a rebore and new pistons to stop it using more oil than petrol.

Have a guess who got to ride at the back of the queue when riding in company.
I thought they wanted to race; wrong, they just didnt want to be sniffing my exhaust!!!

I mentioned the cam chain as a precautionary thing since they are not that expensive (about £35 from Debbens if i remember) and doing a split HYVO with the top end on is very nerve racking to say the least. All those tiny little plates are not suited to sausage fingers like mine!

With the cam cap bolts; they stretch and get 'waisted' at the junction of the plain shank and the start of the thread. It will be obvious if you set them on a bit of white paper and look with a magnifying glass. They're made of drop forged peanut butter and i have had no end of grief so replaced them with some better versions from the local nut and bolt shop for a couple of quid.

AL

Hey Al,
That is serious oil usage. Mine would last to the 500 mile change without topping up, but as I said, perhaps a fix was in place by 1983. I'm only going to change my rings as they definately won't seal now after standing all this time, not because I had problems prior to the bike going off the road.
I'm struggling to get my head around having a split link in the cam chain . Is this a safe option? Did you just grind through the original (taking the neccesary precautions obviously).
As for the bolt's I'll just replace them with quality hi-tensile one's as a precaution anyway.
Col

My J1 stood for 15 years. It too has 10k on the clock.

I ran it up after an oil change and the rings were fine. Good compression, even across all four, and a strong engine.

It does smoke and use a bit of oil though. I think it is stem seals. It used 1 litre on the Germany trip.

I'm struggling to get my head around having a split link in the cam chain Shocked . Is this a safe option? Did you just grind through the original (taking the neccesary precautions obviously).

Strap a cat that would be worrying and novel.
No its a rivet link, you cut the old chain being careful with the thousands of tiny bits and then assemble the chain in built up layers and rivet the front plate onto it.

In reality' you cut the old chain. and using some 6BA bolts, attach the new one to the end of it.
Pull it through and then assemble the link; one plate at a time onto the two new bare ends. With youre third had you pass the rivet link male through and then place the female plate over it all and rivet away.

One hammer behind and one doing the tapping and after two gentle taps it is too tight and you have ruined it
That is if the whole lot hasnt sprung apart in youre hands decorating the inside of the engine with tiny shards of hard metal.

It's easier to do with the top end off because you can take the whole mess out the front or rear where you will be able to see the shrapnel when it lets go.

AL

Phew,
A rivet link sounds better. I saw the word 'split' in your reply and I must have imagined the rest of it .
I must admit, I feel a bit nervous about playing with the cam chain. Anyway, I'll wait until I get in there and see whats required.
Cheers again Al