Sheermadness03
New member
I am in the process of cleaning and adjusting the exhaust valves on my 03 viper. I have made the harness to power the valve servo motor when key is turned on and that works fine. I was expecting that once I turned the key off the servo would move back and allow the valves to close, that don't happen. When the engine is in operation what closes the valves after they have been opened? -Ed
cdi send back information to close the servo
yamaholic22
Active member
Yes the cdi allows the servo to rotate back to the unopened valve position, and the springs in the powervalve block assemblies mounted on the cylinders are what actually close the valves since you can't push on a cable. The servo pulls the valves open, the springs push them closed.
Sheermadness03
New member
Thank you, this is how I thought they worked just was looking to confirm it. -Ed