Just picked a 73 500F survivor from a buddy. Original condition with 5700 miles. Won't get into back story we worked on this bike a few years back got it running with new tune-up parts, started right away. Fuel tank was dirty and carbs needed rebuilding which have now been done tank cleaned and coated. New battery. Went to fire it now no spark. Nothing has been changed since we touched it before. Bike always stored inside. Reluctant to start throwing parts at it. Clymer manual not much help with troubleshooting. Appreciate any experience and suggestions on next steps.