Hey, I'm new to the forum and I have an 1980 GS550. I've had multiple problems with this bike the most recent one is as follows: I can't tell if the fuel valve is on or off. My bike was running ok but I knew it needed new plugs. So I put a new set in yesterday, fired up, go to take off and it cut out. It seems like it's not getting any fuel. I test the plugs and there's plenty of spark. I've manipulated the valve but - nothin' doin. Any ideas? The help is much appreciated.