Strange engine noise CR250

[QuentinCR250]

Hi, I have a 2001 CR250, today after washing it and giving it a start up I noticed a odd sound which I havn't noticed before, when in netural I blipped the throttle, half way through the run down back to idle a whirring sounds kicks in, each time I reved it the whirring sound would kick in as the engine ran down back to idle, the sound is almost like when you spin a rumbly bearing in your hands, could the sound be coming from my crank bearings? or am I worrying too much and is there another explanation for the sound? any ideas would be great.

 

[showtime586]

The last time that I heard a sound like that,I had spun a main bearing. Upon removal, two balls in the bearing had deteriorated and were no longer round. The bearing was still usable, but it needed replacing. Hopefully, this isn't your problem, but a spun bearing makes a very distinctive sound.

 

[QuentinCR250]

Thanks for your reply Showtime I pulled the flywheel cover off and tried to feel for any up or down movement in the flywheel but it was solid, would there be some movement or play in the bearing if the bearing was on its way out?