I have a '07 YZ250F, I weigh 225lbs. I am trying to adjust the rear spring so that I can get the desired sag. My goal is to get it to the sweet spot the manual says (90-100mm). The problem that I am having is that the spring adjuster will not budge one way or the other. The locknut I got loose fairly easy with a bit of pounding. I tried using the hammer and screwdriver to try and loosen it, the same way I got the locknut loose, but no luck. I decided to come here for advice in case I am doing something wrong. I watched a video where once you got the locknut loose, to grab the spring from the rear and turn it whichever way you need to. The manual doesn't say this, and it says to make the adjustments by turning the spring adjustment. I don't have the spanner wrench (or whatever its called). So if anyone has experience with this, please let me know and how to proceed to get my spring adjusted to the correct setting. Thanks in advance.