Not the usual whining noise!

[PunkA$$]

I have a 2003 400ex that just recently started making a very loud whining noise, but only a a certain rpm. It will start at like half throttle and go for about 1000 rpm then stop again when reved past that. I know its not the usual 400ex whining noise I've become so well accustomed to at start up, this is much louder. Any ideas?? Oh yeah its all stock but a pipe, filter, jet kit and some cool stickers.

[Spikers400]

i have that same noise. I think it might be the oil pump... if you turn it off then start it back up does it stop? Mine friends does too, this only happens when it is warming up.

[PunkA$$]

You maybe thinking of the startup whining noise I had also mentioned. My noise is only at about mid rpm and is quite loud. I think what your refering is the oil pump, thats alot quieter. Mine does that too.