My son has a 2010 Polaris Outlaw 90, I found some aftermarket kits. Most came with clutches and springs, pipe and silencer, jet kits and they even had a kit with a big bore cylinder kit. Ill post the web page as soon as I get back home. All the performance mods where simple bolt on performance. Well somewhat simple depends on how mechanically inclined, OK SO I FOUND THE WEB ADDRESSES,
www.maximumrpm.com has some good stuff and the other is
www.lakesmotorsports.com hopefully these can help ya out.