Hey everyone I’m new to the trx forums. I have a 1999 trx400ex (all stock) that I need some help with. I’ve rebuild the top end and carb. Carbs been rebuilt a couple times hoping to get it to work right. I set my air mixture screw to stock and the quad Boggs and dies when I get into about 1/4 to 3-4 throttle . So I added more air. About another turn. I got it to run ok for the first time in a while around the block yesterday, however went to get on today and it backfired and bogged the whole time. I’ve been trying to get my 400 to run correctly for over 6 months with no luck. Any suggestions and help would be much appreciated.