Good KZ 1300 Mechanic in California

Yes LedKZ1300, I do believe that may be the case--I'm not opposed to looking and sourcing on my own. However having a shop that has relationships with vendors/sources is a help too. I entirely agree with you about identifying and sourcing the parts upfront--the last thing I want to experience is a bike that has been torn down with no good parts to effect the repair.
In regards to your other questions, the engine has 60K on it and when it was gone through by the former owner a couple of years ago, the compression was good and leak down results were <10%. He stayed with the original piston ring assembly but with 60K on the clock, there was some cylinder taper and out of round of the liner identified, but not considered severe enough to replace the slugs--the liners are the leading suspect with the oil use. My hope is we can hone the cylinders and reduce the cylinder taper and replace the pistons/rings using the oversize solution I mentioned earlier. I do have access to replacement heads and cylinders, so if I have to go that route, I can. Frankly I'd rather not use them though unless there is no other reasonable option. A good shop should be able to offer this guidance-
The bottom end and transmission are great--and it does not blow blue smoke--but the oil consumption is obvious. Now is as good as anytime to have this addressed.
Thanks again for your thoughts-

So let me interpret reading between the lines.

In order to have determined that the cylinders had some taper, one would have to have removed the cylinder and checked with a dial bore gauge since one could not check the cylinders with the head off and the cylinders still in the bike. Then you suggest that the previous owner decided to carry on and run with the original pistons and rings. That being said, he probably just cleaned up the pistons and rings and then reassembled. And that's why you have oil consumption. The cylinders have a small measurable taper due to wear. and the piston rings would have worn to fit that wear, so the rings are now not round. Now the previous owner cleaned things up and reassembled. This is where things went wrong. It would be impossible to clock the used rings into the same previously installed position so that the rings sat in the bores in the same place as they had fitted themselves to the worn bores so now you have high points on the rings running on high points in the bores and the worn taper in the bores having no contact with worn areas on the rings. If he had torn the engine down to check for oil usage and then reassembled the way I think he did, then the oil consumption probably went up not down.

So what to do now - The proper fix here would be to tear the motor down and send the cylinder out to a machine shop that has a precision hone like a Sunnen vertical cylinder honing machine. (see ) The honing head on this machine has 2 guide shoes and 2 honing stones. It will remove the taper with minimal material loss. (trust me, an Licenced Automotive Technician and also a millwright with 30 years experience in a nuclear power plant and I've spent 100's of hours operating one of these precision hones performing my trades) Then you're now working with a true round cylinder. If the fit tolerance is close to the service limit specs, you could source and replace the piston rings with new ones and get away with the stock pistons. The critical fit is the piston rings to the cylinder walls. So what I'm saying here is that if the pistons are outside of the service limit by a couple of thou I'd run with them rather than a total replacement of pistons and rings (just to save the cost of new pistons).
You did mention that the leakdown was < 10 % before teardown? or was that after rebuild and then reseating the rings? Less than 10% is considered a tight well sealed engine unless racing, then the goal would be < 5%. At 10 % leakdown, oil consumption should be minimal. I would have assumed that if the engine was <10% and was consuming oil, that the oil consumption was attributed to valve seals. That would be evident by carbon build up on the back sides of the intake valves. If you had a bore scope and pulled the carbs, you could see the back of the intake valves to confirm.

I'm impressed that leakdown testing was performed and Kudos to whoever did that. The interpretion of the leakdown testing is the second half of the testing. Understanding what the testing is telling you will save a lot of time and expense. The leakdown tester is a $50 tool. The knowledge of understanding the results- Priceless !!

Hope these thoughts help with your problem.
KB

^^ KB knows what he is talking about.

Still sounds like you'll still need an honest, competent mechanic to have these things checked and done. Also. never depend on anything a previous owner says unless you were a close personal friend.

Thank you so much for the thoughtful reply--the information you provided is most helpful and clearly demonstrates the value of having a skilled resource help diagnose this condition. Personally speaking, I want to "save" this bike and believe there is a reasonable approach to doing so--your explanation and advice provides a good road map to use.
I particularly like the precision honing you referenced and raised and replacing with new rings only. I suppose this approach would ultimately be applied based on the amount of taper or "out of round" the cylinders show. Given I haven't done much searching, are there oversized rings for these 1300's? If indeed the taper can be corrected by a precision hone, then a "ring only replacement" may be available to me--this assumes either new stock rings can be used or if oversized rings are an option as well. Frankly speaking, the bike will not see daily use as this is for my personal enjoyment only.

This exchange has been extremely helpful and provides me with additional options to consider--good options. Many thanks to you-

And thank you too Ledkz1300--appreciate receiving your advice too.
All the best-

I would be very interested what reply you'll get from Johnny's Vintage Motorcycle. Randy's looks pretty straight forward just reading his website. He has all the pricing there, depending on style of restoration, and it's a pretty penny.
I just turned on the 'idiot box' and saw Counting Cars talking about a paint job and some modifications on an Indian. But I saw some definitely Japanese looking bike in the background. Still worth asking them. Of course the best in my opinion would be someone who specializes in Kawasaki's, and Johnny's seems to fit the bill.