Yep, it's definitely not a friction lock.
Here's a tip because I had to adjust mine last summer. I was not able to get mine dialed in at all, it ran too slow and would stall. You only get about 4 full turns on that adjustment knob. I couldn't get mine to idle high enough (even after a link and sync). What I did was turn the knob to its midway position (two turns from a stop). You then have to pop the hood and find the cable linkage for the throttle, it uses a ball and socket style linkage. Pop the socket off of the ball and you can turn the socket end a few turns in and out (it's threaded) to give a better range on the adjustment knob. Turning the socket end out will increase the idle speed, turning it in will decrease it. Give it one turn at a time, snap the socket back on, and then start and test your new adjustments.
This should be done with the engine either on the water, or using a test barrel. Good luck!
