Before you spend too much time on it, check to see if you even have spark. If not, install a new plug (I recommend NGK) and try again. If still no spark you'll need to pull the flywheel and inspect, clean, or replace points. If you DO have spark, drain whatever oil is in the crankcase and add fresh 30wt. Then, with the carb removed, spray a little gas directly into the intake to see if it will "pop" or maybe even run for a second or two. If you use "starting fluid" (Ether) for this only use a VERY small shot and don't do it more than a couple of times, as it will degrade any lubrication in the cylinder bore and could damage the cylinder wall. If the engine fires or runs for a second or 2 you know that you have at least adequate compression to run. Report back with your results.
Michael