...I understand what you're saying, "inconsistent assembly and insufficient quality control", but without a baseline reading on spring tension on a "good" CCT, how would one know a replacement they've purchased is any better than what they're replacing?
Here's another question for you....IF one had an FJR with the typical "noise at idle" chain noise, should one replace the CCT with a new one that might fit into the "inconsistent/insuffiecient" category, or disassemble the stocker, increase the spring tension by one turn, and reinstall?
As I said earlier, "The cam chain tensioner is a touchy feely part without absolute specs." Without previous experience it would be hard to tell if your CCT, new or used is in the range of acceptable. The best spec I can offer is to test it yourself:
Fully extend the CCT plunger. From the end cap of the CCT measure roughly 1/2" down the plunger; mark this point on the plunger with a felt pen or equivalent. Now measure roughly 1" on the plunger and mark this point.
Retract the plunger fully into the CCT. Hold the CCT so that you have a finger on the end of the plunger. Now, using your other hand release the CCT Plunger while trying to feel the spring tension with your finger. Pay close attention to the spring force at the first mark on the plunger rod and note the plunger force at the second mark.
If there is noticeable force at the first mark and almost zero force at the second mark I would suggest that the CCT is outside of an acceptable range. How is that for a solid measurement? You may have to do this test several times to get an accurate feel for the tension. Also, retract the plunger and let it extend while feeling for smooth operation (the FSM test for the CCT). If you are replacing the CCT yourself be sure to compare the old and new CCT and pay close attention to the force at the 1" point. When you install a new CCT, your used cam chain is still going to be elongated. Even though you have a new CCT, it will be functioning at the 1" mark, not the 1/2" mark because of the chain wear.
I have found that even new CCTs have significantly lower force at the 1" mark, but there is still some force there. I can't understand how they could design a CCT that makes strong force when the cam chain is new and doesn't need it, yet has almost no force as the chain wears and needs the force to take up the wear.
I found what appears to me to be variation in new CCTs, most likely caused by assembly. When you buy an new cam chain tensioner you have no way to know what is in the box, it's a crap shoot IMO. That said, when people have the CCT replaced they all say the noise got better. I dunno if that is because the act of installing a new CCT helps take up the chain slack or if the new CCT really has stronger spring force. I will note that at least a couple of people that had the CCT replaced had noise again within a few thousand miles and ended up changing the CCT a second time.
Don't lose sight of the fact that cam chain noise is due to an elongated cam chain, the CCT is just a makeup device. The real root fix for cam chain noise is to replace the chain.