2009 Nytro with supercharger. Have a question about SC belt tension.

[nitroviper]

I bought this sled without knowing very much about it. I rode it once this winter for maybe 10 miles. The belt was making some squealing a little so figured the belt was a little loose. I took it apart today and it did seem a little loose and the pulleys look a little worn. I have the SC install manual but it really doesnt do a good job explaining how tight the tension should be. Ive worked on stuff my whole life and can pretty much feel how much tension most cars belts should have but I wanna get this right since the pulleys look a little worn.

I tightened it up so its much more firm.

Below is a video and pic of what it looks like and the vid is what I sent to the previous owner.

Also the instructions dont say how to check the SC oil level.