So I just finished (more or less) my latest build, a Nishiki mixte for street and light trail riding. I set it up with a 1x7 drivetrain, using a 40t chainring and a SunTour 13-32 freewheel. I bought this neato Shimano Arabesque long-cage rear mech a while back, and I thought I'd give it a go on this bike.

Now, I'm a SunTour guy, so this Shimano stuff is kinda unfamiliar to me. Instead of a B-tension screw (a la SunTour), it has a spring-loaded upper pivot. Servo-Panta whatsit. Supposed to automatically adjust itself, apparently. Lots of people like this gear, so it must work well, right?

Well, I'm not sure yet. Take a look at the photo, if you would, and tell me if that looks right to you. To my untrained eyes, it looks like the body of the mech needs to come forward some. I can move it forward with my hand, but after some shifting, it gravitates back to this position.

Is there any way to adjust this?