Prolly should've dumped this thread in 2stroke Sea-Doo boat section ... but anyway.
Lock to Lock sounds right. That's about what mine is, I do have a different model than yours but these parts are likely interchangeable. Even if I'm on a calm lake at WOT i'm not going to track, always making adjustments at steering wheel. I think this is normal for jet boats, as they sit very low in the water so I wouldn't worry about it. I know it would be nice, my neighbor has a 19Ft SeaRay 190 and you can let go of the wheel at any speed and it tracks perfectly.