throttle adjustment

[dhud64]

I have a quicksilver 3000 throttle control on my 98 Procraft. I cannot let go of the throttle at full speed or it will ease it's self off.. How can this be adjusted?<br />I looked underneath, there is a small hole there, where I figured the would be a 'tension screw', but all I can see is a wire nut. Now, I wonder if someone has been tinkering here before?