How hard, or easy is it to adjust the valves on a Wolverine, and any special tools needed? Also what should the measurement's be? It's a 2000 and they have never been checked so I figure it's time...

 

It's not hard, but a Yamaha service manual will prove to be invaluable for the step-by-step on this and all your future work.

You don't need any special tools, just the typical feeler guage and normal tools.

On a cold engine, the Yamaha manual calls for:

Intake .0024 - .0039 in.
Exaust .0063 - .0079 in.

I would go for the small end of this range, the valve train will not be as noisy.