carb trouble still on my 185s

[teamtigre]

i still have carb trouble on my 185s. i reset the air screw, and the carb is clean, it will pop and crackl everytime i let off the trottle. whats the problem?

[thefox]

Have you checked the timeing?

[kilabeez0]

on my 400ex after I installed a brand new full HMF exhaust I had backfiring. You have an air leak either around the intake/carb/motor or an exhaust leak around the head pipe.