sputtering

[fxnteeth]

I have FMF fatty with silencer, unifilter, (no box). New Stator, new plug, cocoa tannish looking proper plug chop, new plug wire and CDI. 170 main keihin 38 mm airstriker 85 250 R 265CC. Runs very well until high rpm, then sputtering. This occured before the new electrical system also. What am I missing. My next step was going to be compression test and leak down test. It feels kinda like it is rich but, i know it is not. Needle in middle position. 32:1 110 octane then 93 octane to see if there was a difference. I am in Louisiana. What else could cause the sputter? Please help, getting frustrated>
Jarrod

[bigbadktm]

have you checked your reeds recently? mine was sputtering on top end, plug looked ok, but it was running way rich...leaned it out and she quit sputtering