Kind of hard to check crank seals with any spray as the stator is in the way. A leakdown test will confirm bad seals. The easiest way to check bad reeds is to pull the carb and intake and take a look. Several things can cause similar symptoms, the only way of knowing is to check each one.
The first thing to consider is a basic clean and tune-up. Definately check your air filter.
2002 Banshee Ported cylinders, ported reed cages w/Boyeson dual-stage reeds, Wiseco stock bore, Flotek .035 milled head, K&N intake adaptor and filter, Trinity pipes (for now anyway), +3+1 arms, Fox TRX450R front shocks Badass without the big bill
1987/90 LT500 Ported cylinder, ported reedcage w/Boyeson dual stage reeds, Wiseco 530 bore, Trinity pipe with custom fabbed silencer, Custom fabbed 144 front hubs and 115 rears with Motorsport Alloys Tork wheels, Sidewinder chain and sprockets, other stuff It's a Zilla, 'Nuff said