Squeal at ~2000+ RPM

[Qube]

I would... but being a neophyte... don't know what's loose unless it's dangling off the ground and wrapping around the tires

[Blitzkrieg Bob]

pulley and pull or push up/down the belt to feel how much give it has.

If it is more than an inch, it is too loose.

[Qube]

For reference: According to the manual...

Deflection should be about 6mm if the center distance from pullys is 180-280mm. Deflection should be about 13mm if centerline is 300-400mm.