Today riding to work i heard what sounded like a backfire then i had little throttle response. I was hearing popping sounds then but could keep up speed with full throttle. Then i started losing speed with no way to stop it. I pulled off at the next exit to see what cylinder was gone and when i did both cylinders were firing fine and i had full power. now it sounds like i have extra air coming out the exhausts. Also when i give it some gas at idle, when it revs back down it sounds like something is winding down after the engine has already revved down. Any thoughts or info would be helpful. It is an 85 so i know it is an old bike, but it only has 17000 miles on it. Thanks Mick.