The key thing to be garnered from the linked thread was that with a 550 you will likely get the best results by adjusting the tension while the bike is running.
I set the engine by the manual at a static 15 degrees. Loosened the locknut...Now What??
Tighten the locknut and ride away. Here's why:
In theory, when you turn the crank 15 degrees past TDC on the compression stroke of cylinder #1, that is the point of the greatest slack on the backside of the cam chain, where the tensioner is located. So, in the perfect world when the cam chain is in this state all you do is loosen the locknut and the tensioner automatically springs itself into the correct tension. You then tighten the locknut and that's it. But, as have been the experience of many on this board, they tend to get stuck or gummed up and rarely work as intended.
The tensioner screw will have a springy feel to it. As crazypj described, the tensioner consists of a curved spring steel blade with a rubberized teflon coating with a metal bar on each end. Each bar has gear teeth on it and there is a small pinion gear linking them. This is what the tensioner screw is attached to. When the gear turns in the screw counter-clockwise, it pulls the bars towards each other which in turn bows out the blade, tightening the chain.
When TwoTired referred to "rotational pressure", he meant twisting the adjuster screw in one direction or another. If the noise gets worse, go the other direction. Twist the screw back and forth with a screwdriver while the engine is running at idle until you find the spot where the cam chain noise is minimal. As I said in the other post, the window for this is rather small (1/8 to 1/4 of a turn at most), so work carefully for best results.
