Re: 2000 johnson 115hp Ocean Runner - 13 or 15 spline?
2000 should be intermediate gearcase, 13 spline.
The only change I'm aware of is the 90hp E-Tec 25...it uses the V6 case and 15 spline.
The Ocean Runner is just a 60 deg V4 with extra corrosion protection...same 13 spline case as the rest of the eagle series.