Fresh gas, oil level on full mark, clean air filter, compression & spark, do you have a spark tester?
https://www.google.com/search?q=spark+tester&oq=spark+tester&aqs=chrome..69i57j0i512l9.12977j1j4&sourceid=chrome&ie=UTF-8
Remove battery & take to auto parts store & ask them to load test...