Motorcycle Repair: 2002 honda crf450, 2002 honda crf450, clutch plate

Question
when i start my bike it sounds fine then it starts a real bad whinning sound. (kinda like when a shop vac sucks up a hung piece of plastic). took clutch plate cover off, found metal bits. cleaned it out and replaced clutch plates and friction. started it and it stll made the same noise. it is a very high pitch whinning and grinding noise. just want to know what to check next. clutch basket appears to be fine.

Answer
Tough for me to tell you exactly what this is, it could be intake, topend, bottomend, so many things.

Did this start all of a sudden? Was there a crash? The only thing you can do is start with the easiest first.

Can you locate where the sound is coming from?

I suggest removing the carb and inspecting entire intake area...  then proceed from easiest to most difficult..  valve cover, top-end, and then eventually bottom-end if problem's not found.

Let me know after you inspect carb.

Good Luck