I have a 2008 Yamaha Zuma. There is a clutch kit installed and a performance exhaust, but no big bore. Am I suppose to premix the fuel that I put in it or am I fine just putting in regular fuel from the ga station? I have heard that I don't need to because there already is an underseat oil tank. I have also heard I should because of the mods done to it. What should I be doing?