After riding my yz400 all day and bringing it back home with no problems, I tried to start it at my house to check on a mysterious noise I had heard earlier that day. It took forever to get it started where as it usually only takes 3-4 tries. I noticed I was getting a lot of kickback and one of the times it kicked-back I heard a metallic ping noise. I let it sit for a while thinking I probably flooded it. When I came back over and tried again it fired right up. However, the noise I am wondering about is coming from the kicksrarter. It makes the same noise as when you start it and accidentally hold the kickstarter down except more quiet. I stood the bike up and it seemed to slightly affect the noise making it more quiet and ev en making it stop for a few seconds. Whats going on in there? Is this a $10 spring or a $$$$ rebuild?