I don't think anyone knows, or at least they have not reported the longer term effects.
It will absolutely work for the short term and apparently the bike will run very well that way. It might be a bit lean in some engine speed / RPM combinations but again, it has not been actually measured and those who did remove the 'flies and do nothing else never came back and gave any reports after the bike had a bunch of miles on it. ??
Brian
If I just remove the flies will it hurt anything, or do I need a reflash or powercammder.