piston rings

I opened my motorcycle engine and want to change the ring. is amended model Kawasaki KZ 750 1984th On the piston I found the letters "std" upper gap is 1.19mm thick. the second gap, is 1.19 mm thick. I have already bought rings No. 13008-5046. the top ring is 0.97 mm thick. the second ring is 1.17 mm thick. and they are not suitable for me. Can you advise any number of rings exactly what I need to buy :whistle: :whistle:

That appears to be the correct part number for the ZX750, also known as the GPz750. Is that the model you have?
The KZ750 may have and the KZ750 two cylinder models certainly did, use different rings.

By gap, do you mean the width of the ring groove in the piston?

Yes exactly gap mean the width of the ring groove in the piston .my engine nr is KZ750EEII4489. four cilinders

I don't have any 750 part to measure, so I offer a couple of guesses.
1. The rings you got are for a later (1986+) GPZ750.
2. Your engine has aftermarket (non-Kawasaki) pistons.

Thank you for helping

Have you measured the bores and pistons to make sure its worth putting rings in the motor?

Plummen makes a good point. Are you sure it needs new rings? Often when a KZ starts to smoke, the problem is bad valve seals.

If the engine is worn enough to need rings, there is a good chance that a re-bore and oversized pistons are also needed.

A compression test, and a leak down test (before disassembly) could have given you a good understanding of the engine's condition. At this point, carefully measuring the bores is about the only reliable way to know what is needed. A careful examination of the head can also be useful to determine valve and valve seal condition.

If you have already done these tests, I apologize for being redundant, but many noobs jump to the "nuclear option" first, because a systematic approach seems too tedious.

Working with the engine valve is completed. sorry that I've ruined the old engine rings to :blush: