Bore 64 mm, stroke 58 mm, cast iron, port timings: exhaust 170°, transfers 120°, inlet - reed...Continue reading
Bore 64 mm, stroke 58 mm, cast iron, port timings: exhaust 170°, transfers 120°, inlet - reed induction, blow down timing 25°.
The Gran Turismo kit is a cast iron cylinder kit with reed valve induction. The four transfers are enlarged and divided into two main transfers and two Boost Ports. Thanks to the cast iron the barrel can be rebored to 66.5mm.
The GT kit comes with a 25mm manifold for use with the original airbox. Only the cylinder cowl has to be slightly cutted for the reed manifold.
With a 24mm TM Mikuni carb and Clubman exhaust the power output is around 13-14 hp. With an old AF NK exhaust and a 25mm PHBL carb there are 16 hp. If that isnt enough for you there is further tuning potential with the GT kit. The first choice is the larger inlet manifold (item number 8007092). With this manifold the carb is on the right hand side and the battery tray has to be removed for fitting.
The delivery of the GT contains barrel, manifold, reeds, small end bearing, screws and gaskets as well as the high quality Yamaha piston.