It's not the reeds. Bike will run without reeds. Some bikes back in the day didn't even have reeds.
Try checking the pipe for fuel. If the petcock was left on way back when, the crankcase could have filled (not the trans), and puked into the lower bend of the pipe, restricting or cutting off flow. Off hand chance, but it has happened.
For the spark, you either have it or you don't. Sounds like you have it, since it barked out the pipe earlier. Pull the plug and drag it around some if the plug is wet. It may be flooded. See how much fuel pukes out onto the pipe w/o the plug. An old trick with the big bores, try just screwing the plug in 2 or 3 threads so it leaks some compression. No need to beat yourself diagnosing a big hammer like that one. Weak blue of yellow spark, start checking bad ground, plug, CDI, mag, etc. Strong spark will audibly "snap" across the gap.
If it's carb related (as in no fuel or not enough), plug will be dry after all that kicking and pulling around. Squirt a bit of gas in the plug hole or carb directly. If there's sufficient spark, it will run for a few seconds (compared to just a bark out the pipe) even if the carb is empty.
Good luck.
