Hi, you guys might have already read my problem in another post but now I'm specifically tackling one end of my problem. My decompression valve on the cylinder keeps on going up and down when my moped's motor is on. I've been told it should stay in place and that's why my moped sounds like a harley or like firecrackers are going off. Can anyone help me fix this decompression valve problem? I really need to fix this problem soon for my Father. Thanks in advance.