Keeping things nice and tight is not only something that should apply to your nuts and bolts. If there is even a tiny gap in your Yamaha Valve Stem Seal, it can cause all kinds of problems. Let's talk about a few of them. First off, this stem only gets used on the intake side. It is un-needed and will not fit on the exhaust side.However, if it is leaking, it can allow gas vapor to make it into the cylinder when it is not supposed to. If this happens, the head gets what's called pre-primed. This means too much gas vapor has made it into the cylinder, and the next time the spark plug goes, you will hear a loud gunshot sound. This is a backfire. They will scare the pants off of you and are not suitable for the caddie. In fact, they can further damage that seal, making the problem worse and worse. Call Buggies Unlimited and get your golf cart valve stem seal coming.