For 6-8 Horsepower (7 tooth spline & Thru Hub Exhaust)
6HP (2-stroke) '86-'00
F6 (4-stroke) '01-'10
8HP (2 stroke) '86-'09
F8 (4 stroke) '01-
F9.9 (4 stroke) '08-
F6/8/9.8