Herd this almost grinding like noise from my engine when I got to about 6k rpm and stops shortly after if I keep increasing my rpms. If I stay at 6 or let off it keeps making the noise to I drop to idle almost. Doesn't do it every time I hit 6k only sometimes. Herd it few times today so I'm afraid to ride it till I figure out what it might be.I dont have a ton of money and time to just take it in and let them take everything apart and find it for me so I was hoping you guys might be able to help. I'm thinking it might be the vavles but I'm not getting any lose in power/performence. Bike has like 47k miles on it and its an 04. Changed clutch at like 30k so dont think its that but havent done my valves like I should have so thats why I think that but any input would be nice. Thanks again.