A traffic stop in Hood River led to multiple felony arrests after officers say they found weapons, suspected drugs, and a concealed firearm.  The Hood River Police Department says an officer stopped a motorcycle Wednesday after the rider allegedly ran a stop sign and was driving without registration plates.  Police say the driver and passenger immediately began passing items back and forth after pulling over.  During a search, officers say they found brass knuckles, two loaded magazines hidden in specially made pockets, a small amount of a white powdery substance, and two unidentified pills on the driver.  Police also recovered a loaded handgun from the passenger, exactly where the initial officer had directed responding officers to search.  Investigators say the driver is a convicted felon, and the passenger did not have a concealed handgun license.  Both suspects were booked into the Northern Oregon Regional Corrections Facility on multiple charges, including felon in possession of a firearm, felon in possession of ammunition, felon in possession of a restricted weapon, unlawful possession of a concealed firearm, and tampering with physical evidence.