This video shows how an exhaust valve works and how to maintain your exhaust valves if they become corroded or dirty. If you can hear any squeaking or noise coming from your valve when you open them, they are likely dirty or corroded and there is a simple solution for this. Simply spray some electro wash inside the valve rod, followed by lithium grease to fully lubricate the mechanism. If you notice black smoke coming from the exhaust, that is due to an engine issue, and that black smoke can cause carbon build up in the valve flap and cause it to malfunction over time. So be sure to maintain your engine properly which will in turn help you to maintain your exhaust valves as well. Thank you for watching another video from Top Speed Pro 1 and let us know your thoughts in the comments below!