Hey Im new to 2-strokes. I started riding 4-stroke 450s since 2005 and havent really rode anything else. I was on my brother's 1999 Yamaha yz250. I have learned that those bikes love brand new sparks each time they are ran. No Problem there. Here is my problem. After a 45 min ride, I ride back to camp and the bike acts like its out of Gas. Ok, easy fix, I just walked it in and filled it with Pre-mix gas. After it was full I started to go back out to ride and as soon as I started it back up I shifted into 1st gear and got on the throttle and NOTHING. just completely died after trying to put on the throttle out of 1st or 2nd gear. What is that all about? Stuck valve or stuck something? I don't know. Help please. thanks, Steven.