11. High-speed impact takes its toll on all reed valves , with metal valves suffering in fatigue. 12. The Cox line of reed valve engines designed prior to 1960 used a rear reed valve induction system. 13. The Cox line of reed valve engines designed prior to 1960 used a rear reed valve induction system. 14. In some two-stroke engines, a Helmholtz resonator is used to remove the need for a reed valve . 15. In a reed valve engine the valve is drawn open by suction as the piston moves upward on the compression stroke. 16. As the piston moves down on the power stoke, the pressure in the crankcase causes the reed valve to close. 17. In 2010, an after market R / C throttle / choke has been developed for the . 049 reed valve engines. 18. The 2CV's engine has a combined engine " breather " and oil filler assembly which contains a series of rubber reed valves . 19. The air / water duct is drained by a reed valve , which if clogged can cause water to overflow into the passenger compartment. 20. The 593, ( more commonly known as the Ski-Doo 500ss ) is a 600cc version of the reed valve 493 engine.
