My uncle recently let me have his 2008 zook so I could race the summer and winter nationals at Ponca and Mini O's. The bike was a brand new left over "08 that he bought in 2010. The bike is 100% stock except for the fmf slip on. It is sputtering out in low rpm's really bad. The only time it runs awesome is when really high in the rpm's. I've heard it needs to be remapped or I should run strictly race gas. What do you all think? Any help would be greatly appreciated.