1999 25ESHX Yamaha 25hp 2 stroke throttle return spring?

[MikeHauck]

I put a new tiller assembly on the motor today with new cables, the throttle is working but isn't turning back to idle when you release it. It was returning before I took it apart, now it just stays in the same place the wing nut on the tiller isn't tight and the handle turns freely. I took the assembly out that the cables hook to on the motor end to get the new cables attatched. I though I kept it all together but notice in the parts diagram that there are 2 band springs in there, is that what returns the throttle to idle or are there springs in the carb that do it? the springs are #7 and #8 on this diagram. I was wondering if I could have put it together wrong? I started it and everything works great it's not binding it just doesn't return.
1999 25ESHX Yamaha Outboard CONTROL Diagram and Parts

If I can ask one more thing part #25 on the picture the DIAPHRAGM ASSEMBLY. What does it do? There's just a plunger that hits a another part sometimes, no wires or hoses connected it's 108.00 dollars so it must be important, I was really curious what it does and can't find anything on the internet. I hope these aren't dumb questions it's the first time I have worked on a outboard, a really appreciate any help, thanks! Mike

[MikeHauck]

I got it figured out.

I took the throttle cables loose from the bracket on the motor and the outside piece that hooks to the magneto was free and springy, the inside piece which has a separate band spring was binding, this loosened up when I loosened the bolt holding all that stuff on there. I took it apart pushed the band spring it good and carefully put it back on, tightened it up and both were good and free. No exactly sure what I did but I had something wrong. I put it back together and tighten down the throttle cables checked it and it's binding! Dang. Turns out I need to set the top cable that pulls the throttle open then just snug the bottom. I was adjusting both sides tight which pulls the whole thing against the shaft. Seems really dumb now but it's working great. Hope this helps anybody who isn't familiar with this stuff. The roller that rolls on the cam has a flat spot on it and it slides instead of rolls, i think it's on the piece close to the idle adjustment, thanks.