I have just fitted an arrow exhaust to my sons 2007 xt 125, I have not removed any thing but the complete system. I had trouble starting it but this has been adjusted by the small brass screw on the right side of the carb, (looking forward) I set it to tick over at 1300 rpm but when i turn the throttle it bogs and cuts out if i don’t come off the throttle. Increases the tick over to 1500 /1550 now the bog is very slight with a quick throttle, slow twist and a bit of slip and off it goes. Seems to pull well up around 8000 rpm with good pick up but there is a slight back fire, big pop. It sounds nice but not sure if it will do any damage. I can’t find the air fuel mixture screw as i think it is running a rich, (or is it?)
Is this the typical for a sports exhaust needing hi revs to give more beans at the top.
Can I, how do i adjust the air fuel mixture? Do I need to put a new jet in it?
All help gratefully received