It will still not be the stator. The stator only generates power when the engine is already running.
If you have week spark then the area to look at is your ignition system. This starts with the battery and wiring. if you have tried a different battery, then you want to check the wiring running to the points AND to the coils, especially the coils. A lot of the coil connections will rust up. You will want to remove the connection and clean it all up very well.
What color is the spark? How strong does it look? Spark of course should be blue but it should be a strong spark. If you ground the plug and watch the spark, if it is weak, then it will be much weaker under compression.
Check your plug boots for resistance. It should be About 5000 ohms if it is higher, then it is time for new ones. Make sure your plugs are also D8EA if you have a 69-78 cb750. Make sure there is NO R in the number. R denotes a resistor plug. You can also clip about 1/2 inch off the spark leads and then screw that caps back on.
Now without knowing what you have for ignition, I can only speculate. If you have points, check them for pits and spikes. These will not allow the coils to charge right. the gap on them should be .012 - .014 fully open. They should also JUST be opening at the F mark.
The ride IS the adventure. The destination is just to get gas!