I have a 2001 Yamaha Warrior with a stage 1 Hot cam. I was wondering if i should get a full system or just a slip on. And which slip on or full system should i get?  

i have the cobra slip on pipe and im not happy with it at all. its excessively noisy and not repackable either. when i go to replace it next summer i think i will probably go with the t-4 procircuit full system. i run that system on my 400ex with the 440 kit and im very happy with it so far. its a little pricey though.