New subscriber, first post. My 90 VR that I've had for about 6 months was running great, on the way home last month. All of a sudden it started running rough acting like it was running out of gas, I had just filled the tank. Choking it to keep it running couldn't give it any throttle I made it. First I changed the filter no luck. then I got busy. I drained the tank no trash no water, checked the fuel pump it would pump gas across the garage. Took the fuel line loose from the carburetor inlet turn the key I'm getting gas at all four carbs. It will only run when I spray B12 into the throats. I inspected the diaphragms couldn't see any tears or holes. I cleaned the jets and replaced the intake boots. I don't know what else to try. OH I for got I let sea foam set in the carbs for three days, changed the plugs, installed a new stator and a used starter clutch. Its turning over really good but still won't start. Can anyone help me?