Have a 2007 ktm 50 senior adventure for my son. its brand new with only 4 hours on it my question is. the bike runs well but it boggs at idle and wont idle for long maybe 15 seconds but runs nice when continually reving

You likely need a smaller pilot jet in the carb.

Try screwing the air screw in and out - if screwing it out seems to help then you need to change your pilot (low speed) jet. I don't have any recommendations for you as far as size, but just get one the next smaller size from what's in there now. When perfectly sized, your air screw will like to be set around 1.5-2.0 turns from seat.

This could also be a sign that you need a new ring. The rings don't last long in these bikes - you need to re-reing quite frequently. it's a very common thing. Lower compression from a worn ring will make the motor act as if it's too rich due to incomplete combustion and lower combustion temps. A worn ring will show up at lower engine speeds first- much like you describe.

Scott