Hello, On my engine it says 71-1033. I cant find a number on the frame, near the handlebars on the right side where I would expect to see a frame number its stamped "Laughing Madness" Whatever that is... Any idea what this engine number means and why theres no frame number? I believe my bike is a 1970 Lightning.
A few things that will tell you real quick if your bike is a '70 or not would be the swingarm, there should be a solid shaft with bronze and steel bushing rather than the earlier tube with rubber bush . Then there are the two tubes welded to the headstock for a fairing mount . If you have both of these it is a '70, the numbers should be stamped on a squared off lug on the drive side front motor mount .