Just got a really nice 99 ZR 500 EFI. This is probably one of the newest sleds I have had so I don't know much about it. Seems like when it sits on it's own it stands up nice but as soon As I sit on it (245lbs) it goes down a lot. I have the springs set on the highest setting. My first thought is to replace the rear springs as they are likely 20 years old. I know all the shocks were recently rebuilt as well. Any other suggestions would be great. I'm good at fixing things but the setup has always been my weak point.