Have a question,im fairly new to gas,maiden my firsyt flight with my DL50 yesterday,ran great i have about 31/21 -4 tanks through it,my question is while in air between 1/4 and half throotle was burbling or missing sound often but when i hit t hrottle sounded greast i know its supposed to run rich for few gallons i think when should this go away or when should i help this go away ?