Hi everyone. I just put a new Modquad K&N air filter on my 400 ex. I bought it from Rocky Mountain Atv. I installed it properly and it fits tight and well. However when i hit the throttle hard it boggs down and almost stalls out. if i let it ride out slowly it will ride. And 1st and 2nd gear are better than 3-5. once i hit 3rd it wants to stall and i have to down shift. Do i need to jet it?