AZ Quad Parts 421cc Athena Hotrods Complete 68mm Big Bore Stroker Kit. This Is The Only +4mm Stroker Athena Kit On The Market! This Is The Complete Top To Bottom Motor Rebuild That Will Compete With The Cheetah Cub With A Fraction Of The Cost! With proper tuning on pump gas you can easily hit 95+ hp with this kit! Fits Yamaha Banshee YFZ 350. Years 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006. This 421cc Stroker Conversion Rebuild Kit Includes. Athena 68mm Big Bore Nikasil Plated Cylinders (Pair). Full Clean Up Port Job With Tunnel Porting. AZ…