judging by ear, I do not have a tach. If I set throttle at full power (link rod to governor starts to bow, as if up against hard stop), I can manually pull linkage to carb and rev up significantly more. Looking at the shop manual, for what it's worth, I only see a spring right on the governor.......is that the only control spring in the system? Mine has another from carb linkage to alt bracket, pulling carb open, and, if it were stronger appears would resolve my problem, But I don't see it in the manual