Had the blue 450 in the shed all winter. It never ran right, combination of everything. I adjusted the valves and never got spark. Put new plug wire epoxied into a coil, checked compression. Odd readings. Different handlebars and controls since doing plug and play in putting the 450 chopper back to stock, etc.
So it sat since about a year ago , cranked it up, tested the plugs and bright blue spark. Put it somewhat together and it fired up, took it for a blast around the section line. It runs better and quieter than ever, no chain or top end clatter. Probably the first time it had a valve adjustment in 40 years.
Now to find some kits from the carbs or aftermarket substitutions- mikuni .