I got a 03 Raptor and I Have had it for about 3 Months now and I just Took it in for Service Check up and they said the Valves and Stuff needed to be Adjusted. So they Adjusted my Valves and I just got my quad Back Yesterday. So When they adjust the Valves does that make a big difference in Top Speed or anything. Will it make it go Faster or What?

 

You would only notice a difference only if they were grossly out of spec. Other than that, NO. It's routine maintenance.
I beleive they recommend it every 6 months to a year on the Raptor.