Description Model/Year Cyl. Bore Size Sleeve Description Thickness O.D. Sleeve Length Type Brand Part No. 250 hp 99-00 6 3.540"(90mm) Square exhaust 2.320" wide, with compression relief notch N/A 3.923" 6.350" RS Advanced 1107SB Cylinder Sleeve: Yamaha 250 Hp 76 Degree 99-00 Straight .020 Over Yamaha 6 Cyl 3.544 Bore 76 Degree 250 1999-2000