I recently bought a 1997 Javelin with a 150 Faststrike. It had been sitting up for awhile. The speedo, at first, would stay stuck on 30mph. Now it's stuck on about 25 mph. The fuel guage indicator would also go back and forth from empty to full. Is there something that might clog up the speedo tube, and if so, do you just unhook it from the bottom front of the motor and blow through it? Thanks