Ok im gonna be honest i dont know much about fourwheelers i just know the basics I bought me a 2004 yamaha big bear 400 2x4 this year around tax time and it ran but not very good i put new gas in it and it never ran right so i bought me a new carb from amazon for $60 it fit right in and i looked up to where u have to adjust the air flow so i did that and it ran alright for awhile but never right And then it finally died on me and wouldnt start back just the other night i decided to re adjust it and it started rigjt up and ran perfect and i put the filter and intake back in and killed it and tried to start it back and it wont and i cant seem to find the right adjustmen Did something go wrong??

 

The original carb probably got some dirt in it from the tank. New carb would run OK until it got dirt from the tank. You adjust it and it gets more fuel, so runs until it clogs again with more dirt from the tank. So, clean the carb out and fit an in line fuel filter. Not a panacea, as the paper ones tend to air lock if run dry. So, if you run out of fuel, put it on reserve, the filter air locks and you are stuck.