kz900 piston/ring options?

I know my 76kz900 A4 needs new piston rings. It runs OK and burns some oil. My plan is to ride it as is until next winter. At that point another newbie will enter Maintenance Land.

I realize that I won't know exactly the extent of the engine work required until I open it up and inspect and measure the bores etc.

My local Kawasaki shop says that OEM rings are not available. With that in mind, I am seeking the wisdom of KZR members.

If stock size rings are all that is required, what is the quality of aftermarket ones, or are OEM rings available elsewhere?

If boring and new pistons etc. are required, what are my options? I don't want to go the high compression route. I believe the Wiseco 1015 gives 10.5:1.

I see that Z1E has a limited supply of OEM oversize pistons and rings but they are pricey compared to a Wiseco kit which includes pins, clips, and gasket.

Would it be worth while to plan on boring, and stockpile OEM oversize pistons/rings, or are there other low compression options?

Will boring necessitate re-jetting the carbs?

It is a ways off until I so this work, but I am the type of guy that needs to ponder, plan, and procrastinate. Budgeting and saving is part of planning and procrastinating.

Z1E has the new rings in stock for your stock pistons.
www.z1enterprises.com/detail.aspx?ID=193

otakar wrote:

Z1E has the new rings in stock for your stock pistons.
www.z1enterprises.com/detail.aspx?ID=193

Blarg! beat me to it... :laugh:

Ditto, Z1 is your best bet.

if you decide to do a re-bore the wiseco 1015 kit works very well the compression is just about perfect for street use. not so high that you'll have detonation problems, that it makes good power on and high enough that engine will make good power with premium pump gas. a win- win situation and the nice thing about is that your still using the stock block so the bike will look stock if your concerened about that

I intend to keep this machine for a LONG time and put a LOT of asphalt under her wheels. To that end, I would prefer to stay away from high octane fuel as long as possible.

I suppose my concern is how long will stock ring sizes and stock oversize pistons be available? Or are there aftermarket low compression units available? Or should I stock pile OEM oversize units while they are still available?

This a difficult question as I won't know exactly what I need until I take it apart. I am concerned about the dwindling parts supply. Will low compression oversize units be available in a years time?

This bike has more than enough power for me as it is.

I see piston/ring sets on Fleabay from time to time.

If for some reason replacement rings become unavailable I believe you could have Total Seal make a set of rings for the bike. They have been very good in building ring sets for oddball applications for me. You will need to know the finish bore size, the width of the ring grooves, and the radial depth of the grooves.

This website should have a lot of Kawasaki parts:
www.excite-webtl.jp/world/english/web/?w...&wb_lp=JAEN&wb_dis=2

Thanks for all the input. Gives me food for thought. Think I'll chew on it for a while, stop obsessing, and worry about it when the time comes.

That Japanese web site is hilarious. Nice stuff though.

Since those rings that Z1E has, are repros, they should be available indefinitely. If you ask Jeff, he will tell you so. Also realize that Honda Yamaha and Suzuki all use ART pistons, you should be able to get replacement pistons for a very long time.