If you have too much slack in the cable, the TPS (throttle position sensor) will not open the power valves appropriately. When I got my '05 M7, it ran ok but just didn't have that hard pull on the top end. Had the mechanic come up to the mtns. and we plugged in the computer, sure enough the power valves weren't even opening! We adjusted the throttle cable which in turn brought the tps into sync. Problem solved.
Now several times a year I check the sensor. With the machine off, I smash the thumb throttle, and adjust to where I hear a faint tick of metal opening all the way. If you tighten too much the power valves will open sooner. Some may like that idea, but I like it stock at around 7,200 rpm.
I had a mechanic actually adjust the TPS by taking off the system then plugging into a computer, but the way I check/adjust is the same way the mechanic did it when I first bought the machine.
Hope this helps.
Mark