Primary chain slack

OK, I have searched and read several topics on primary chains. What I have not found is worth posting. How does one go about measuring the slack in a primary chain. Can it be adjusted or just replaced. I have bought a new one just because I didn't like the slack in mine and I'm replacing the crankshaft anyway. Gurus, have at it! How do I get and keep that lower end tight?

this was my ebay pic

There's no tensioning of the primary chain. It just eventually gets noisier and noisier as it stretches and becomes more important to keep carbs synced to minimize clattering noise. They last a long time. If your carbs are synced noise is minimal even on a worn chain. I went 162,000 miles on my chain and the engine was still running and not all that noisey with the original chain.
I think you measure slack in the center of the chain similar to your drive chain and there is a wear recomendation in the service manual I believe. I don't have it in front of me though.

It was mentioned in "Primary chain stretch limit" that 27mm is the point at which slack is considered excesive. I took two measurements today, and found 33mm OD slack and 48mm ID slack. Either way I look at it, I'm glad I have a replacement. She did make a lot of low end noise last summer. Could this have caused any damage? Has anyone had any problems directly related to primary chain slack?

I have not yet mastered the multi pic post ;P

How many miles are on that motor?
I have disassembled a few GPz750 motors and I have yet to find one that bad.

just under 27,000 miles on her. It makes me wonder how hard she has been beat on for her first 24,000 miles before I bought her. Thats why Im quite happy to be doing a complete rebuild from the bottom up, Im looking forward to many good years with her.