This is an upgrade to change your STM Bellow Style Valves to the new Piston Style they do not come with blades. Only works with STM valve blades!
ALL NEW DESIGN!
We have upgraded our exhaust valve technology from a membrane bellow style actuator to a piston style actuator. A much simpler design that uses less components and eliminates bellow failure in big bore and turbocharged applications. Our piston mechanism stays lubricated by the engines 2 stroke oil sytem and is actuated by the exhaust pressure from the cylinder. Same design works well with naturally aspirated engines as well. We developed this valve design in the fall of 2010 and tested them on turbo charged, and naturally aspirated engines throughout the season with amazing results. You will love the throttle response gained. Say good-bye to failed servomotors and stretched cables. There is no need to play with cables or the reprogramming of your cdi to change the opening rpm of the valve. You can adjust the opening rpm by changing different thrust springs. We do stock different spring combinations for finer tuning- Kit # 78SPNG sold separately
Applications for models 2007 thru 2013; part# 66PVP will change over to your valve blades and upgrade to the piston style valve. Gaskets, fasteners and tools supplied.
F8 & M8
F8 HO & M8 HO
F1000 & M1000
F1200 & M1200 BIG BORES
The valve housing is made of billet treated aluminum. Overall dimensions are
2 7/16” high x 1 3/4” diameter measured from cylinder mounting surface.