Make sure to lube up those adjustment screws, else you'll be working pretty hard to adjust. The adjustment screws description and lube is noted in
Post95 and
Post96.
I used WD40 and it wasn't bad at all. I guess just make sure to allow some time for the WD40 to get in there and clean those dirty screws. I waited about a minute or two. The adjustment screws aren't "tightened" or "torqued" so it should require something like PB Blaster. The screws are "free", and should adjust with little force.