Carb, spark, engine wear.
Compression reading, those are well known for low/no compression due to owners never setting valves since they were shim type. Need 170 psi.
Could be carb but then all owners think that and why so many of the bikes have totally screwed up carbs, they chase them until they are damaged from all the times into them, no carb work in the universe fixes a low compression cylinder. I used to buy and sell based on that simple premise, they ALL think it's the carbs.