The best way to sieze a blaster is to make significant changes to airflow, and only think about the main jet. Most siezures occur for 2 reasons...
1. airleaks
2. lean mid throttle position
think about everyone you know that has seized a bike.. they are screaming along wide open, they let off for a second and screech. if your needle is lean and your running wide open, the main jet flows the fuel, but as soon as you back off, the needle causes a lean condition and can cause an instant and radical temp spike. If the main is jetted right you only have about a 100~150 temp range before you melt the piston. so when you back off and the piston temp instantly jumps 200 degrees, bye-bye.....
You actually want the needle a little rice than the main, so backing off cools the motor slightly.