hello, i bought a 93 xt225 about 3 weeks ago. it ran pretty good when i bought it, but i was only about to ride it in a parking lot. getting it home and taking it to the woods i noticed some promblems. it misses, the carb was cleaned before i bought it, and i changed the gas to 93 octane and cleaned the air cleaner. also after about 30 minutes of riding it, it dies, and won´t crank back up. let it sit a while and fires right up. don´t know a whole lot about bikes, just got this as a way to get into the sport and i love it, all 30 minutes of it anyway. Any suggestions...