I have an 86 venture royale. I was riding home from work today and the tach quit working I had power loss. I put it I first gear and revved the engine up a few times. It started backfiring a few times then the tach started working and got all power back. Any ideas? Also does anyone know what the hose coming out of the top of the gas tank is for. the hose is going from the top of the gas tank and runs up to the front of the bike nut not connected to anything.