my friends mojave has a full big gun race exhaust system, k&n air filter, and jet kit on it. when he starts it up and hits the gas, it bogs out. He also put a new spark plug in it. Can anyone tell me what the problem might be?
Thanks

 

he needs to rejet

 

he already did and it worked fine for about 2 weeks and now it bogs out again

 

Drain out all the gas and put some new gas in, some water got in my gas and that happened. Another thing is try different jet needles maybe.