Did you know that aux port bikes cough like that if theyre too rich? I've see that every time I start my 50cc hobbit before it warms up.
I've done lots of aux ex port cutting and they love lean needles. The scavenging is so good and they pull charge so hard that if you use a standard needle it'll often be mega rich.
That being said, your main ex looks way too big, very snaggable