Yamaha xs650 top end rattle

This noise turned out to be caused by the previous owner who decided to "rebuild" the motor himself. He decided to replace the lock washer on the oil pump drive gear with a flat washer, and when i tore it apart both the nut and washer were laying in the bottom of the pan and the gear backed out and was no longer being driven. The top end was not getting oil and the rocker arms were worn like crazy. There was also orange RTV EVERYWHERE inside the motor.

[@Cj_Metal_Crafts]

my xs makes the same noise when the engine is cold when it is warm is stops.could be ur timing chain or valves needs to be adjusted

[@NielsMF]

valves