I have a Two Bros. pipe on my 99 ninja and I love the sound I get outta it. I havent had any problems with it except I havent jetted my carbs yet and at around 7,000rpm it loses power and then at like 10,000rpm you get back the power. I think if you jet it it will give it the fuel needed through out the powerband . Also it really sux when that happens when when your in a 3rd gear wheelie.