I have a 2003 Yamaha warrior 350, that ran perfectly fine then one day I started it up, and it idles fine but when giving throttle it will backfire/bog down and then die. I replaced the carb, and plug and still have an issue. Anyone know what else I could do??

 

Couple things to check:
1) compression
2) carb boot for cracks (air leaks)
3) valve lash
4) timing