around 40 mph and stops at? the noise stops at around 65mph the cv joints look good to me but its hard to tell and i dont know how to test the or anything else
may be the exhaust pipe. mine was loose for a while, and it'd make loud crackling noises under the passengers seat when ever I rode frum 30 - 50 km/h. You may just wave to weld it in place to secure it. Take it to a shop n check it out. Hope that helps =D