Werks Racing have announced the release of their new B5-Pro and B6-Pro engine. They left the basic performance characteristics of the aggressive bottom and strong mid/top of the B5 and the super smooth and linear power band of the B6 in place and just made them better with these new Pro versions. By incorporating ceramic rear bearings and a lightened and epoxy filled crankshaft in the Pro versions, engines will now spool up faster providing increased acceleration and fuel economy. Black anodized crankcases not only look sharp but also provide for increased heat dissipation. A billet CNC machined rear back plate reduces weight and increases rigidity of the case assembly. A new heat insulation sleeve material improves carburetor performance and reduces the likelihood of heat saturation. Finally everything is topped off with a new, large diameter cooling head which not only improves heat dissipation but also lowers the overall CG of the engine by reducing weight by 5% over the standard B5 & B6 heads and an amazing 10% over their 2010 head design.