[sho305]

They do make a normal noise at high speeds, it is the cogs in the belt I believe on the bottom of the secondary. It only does it when fully shifted out, at full shift the rpm will start to rise. Sort of a buzzing/whirring sound. At golf course speeds it never happens unless you coast down a hill when it is not running you hear it. But it should not be that loud, you might try a new drive belt the cvt usually works poorly with a worn one. Yamaha lists 1" wide as the wear limit, and by then they don't work very well. They are 1 3/16 wide new. If the noise is metallic that could be bad and likely a clutch issue. Rare but could be a transmission issue also.