top end noise problem!!!!!PLEASE HELP!!!!

[chrishd2008]

i have a 2005 polaris predator 500 troy lee edition and it runs great but all the sudden when i go to rap it out i get aloud ticking almost like valve clatter and it wants to slow down like something is draging it could it me my automatic decompresoner?????? ive checked all of my valve buckets n stuff and every thing looks good idk only at hight rpm it does this and its happened all the sudden it still has good low end thats how i know the crank is not bad and i have a pro com cdi box and i also need to be told on how to time it please help!?!?!?!?!

[katch26]

this is just a guess but if it happened all of a sudden it sounds like the timing chain skipped time which would explain both the noise and power shift. Pop it open and give it a looksy. Its very easy to check and no harm if it looks like its good

[Polaris 450MXR]

Could also be valve springs? My 440ex did something similar. I had a rev box on it and at the top end it would pick up a valve float and almost made it sound like i had lost the exhaust and everyonce in a while i could here the valves hitting. I put heavier springs in and never looked back.