Title sums it up. The 4-wheeler at the non-profit I'm affiliated with hadn't had an oil change in at least 2 years, they use it frequently. We'd really like an affordable option that I can do to fix.

Sound is new after changing the oil (with official Polaris kit specifically for the vehicle). Instructions from Polaris were followed exactly.

I've uploaded a video that hopefully makes the sound audible. It seems to me to be coming more from the cylinder area than anywhere else. I have another video here showing that the sound increases with engine speed, and it's obnoxiously loud.

Please let me know if there are any additional details I can provide.

Everyone involved is fully aware that at least 2 years is too damn long, so if we can skip any admonishments, that would be appreciated.