82KZ305: With your experience or lack thereof in this matter, your REALLY need to find some competent help with this project. I don't know where you live, but if you let us know someone may volunteer to give you a hand or at least recommend a person or establishment to give you some assistance. Measuring engine dimensions is no easy task and requires some very specialized tools. This is not an endeavor to be taken lightly and just anyone doing this isn't going to cut it. You most assuredly don't want to install a new block or pistons and have the same thing happen. Let us know where you are at.
Rick H.
Oh I totally agree, been saying that from the start. I have a very good idea of my abilities and the finer points of engine internals is not among them. But I'm also poor so necessity dictated that either I did it or it didn't get done.
I took the piston to my local powersports guy and he didn't think the wear was much to be concerned about. The wear is on the points where the piston is widest, he explained, and he showed me other pistons he had laying around that had similar wear patterns, front and back only. Plus there's the possibility it wasn't lubed properly when I reassembled. So maybe this "new piston problem" isn't a problem? He showed me how to work with the rings and check their gaps and I ordered a new wrist pin, just in case there is wear that my existing tools can't measure. It was cheap insurance. He also gave me some assembly lube and said he would help if I needed more help. But I can't afford to have him do all the work.
Been thinking about the piston to cylinder clearance and wondering if I really need to worry about that. Its a new Kawasaki piston (with 14 miles on it) and a used block that has been measured and honed to specs. It seems to my (inexperienced) way of thinking that too little clearance is highly unlikely if not practically impossible with a stock OEM piston and a used, freshly honed cylinder. And there's nothing I can do if clearance is larger than specs, since going oversize is not an option. But feel free to correct any errors in my reasoning.
Cleaning the carbs now and was planning to start putting back together this weekend. I'm in NE MN, far from humanity.
PS-I also noticed when I took my carbs apart that the JBM vacuum diaphragms I installed 2 years ago don't really hug the slider cylinder very snugly. Caused me to wonder if that was part of the reason I couldn't get the bike above 45 mph, as that sounds similar to symptoms of leaky diaphragms...just a thought. I reached out to them but haven't heard back