I just set my bypass tension a month or so ago. The manual has a little guidance. Most important is to know that there is a locknut under the bolt head that must be loosened before the bolt can be adjusted. Also, those buggers are tight and if your wrench slips you can slam into the back of the catalyst. The way to adjust it is to feel the required effort to "cam over" the bypass lever. You should feel and hear a noticeable click or clunk when you close the bypass. Not too hard but not so soft that the cam over is ineffective.
Turn the adjustment bolt by no more than a quarter turn at a time. I went a quarter turn and think I might have gone too far as it is pretty tight now.
Before you attempt adjustment, lube the bracket where it rubs the operating rod with high temp antiseize. That alone will make the bypass act much differently.
