I am looking at buying an aprilia 125 sx 2008 and was wanting to know what if anything i could do to deristict it . And if possible what would be the difference in speed gained thanks

If I were you I wouldnt even consider buying it. My son bought a brand new one on October 08 and it has already seized twice through no fault of his. Aprillia have an appauling customer service and it now sits in the garage redundant at 8 months old!!!