I searched threads with little info- the FMF's seem to compare favorably to HFM etc.. both in price and quality- my main concern is also noise level- I don't want to be obnoxiuos- or go deaf..

http://www.fmfracing.com/application...;model=KLX250R

 

I'm not sure what the db level is but I have heard some of the FMF's can be really loud. I had a FMF Power Core slip on on my Z400, sounded great and I didn't find it any or much louder then the full Muzzy I have on the 250. I really like the look of the FMF, nice pipe.

 

The Q2 is pretty quiet compared to most aftermarket pipes. The powercore 4 is loud.

You will need the headpipe from a KLX300 or 250R to make them fit the 250S, unless you know a good welder/fabricator.