Sounds like it possibly could be at one HP or 1.5 HP which needs to be up to 2 hp specs,
Thick springs like super stiffy kickstart springs would be an improvement but if the bike was at my house it would rip to Hi 30s To 40 mph in a few hrs because Jetting/timing/tuning and gearing jetting means everything!
The one jet off or one needle clip selection off and or or timing off and your bike is a dog
But if you’re not you could rip beating small compact cars to 40 mph!
Puch brand mopeds are about the most easiest mopeds there are yet the most hardest