Hello,

Recently I installed a new carb, air filter and plug on my 2000 Big Bear 400. Everything went great it was pretty much plug and play. The problem I have is when I give it full throttle, machine starts to spit and sputter. It will run fine until that moment, once I back off it will run fine. Not sure what I need to do to adjust any ideas? Thanks

 

I have a feeling you can't adjust the main jets on those carbs. On some, you take the needle out of the CD piston and move the tiny circlip into a different groove, needle up for richer. Only other thing is a slightly bigger main jet. I would fit the main jet out of the old carb and see how it goes.

 

If it is a Chinese aftermarket carb, there will almost certainly be adjustments needed. Everyone I get runs lean. I would first exhaust all efforts to get the OEM carb cleaned and working.