Should be about 150 cranking with the throttle wide open but if it’s around 100 it won’t run. Compression gauges vary greatly but it will give you a general idea. If you get a rebuild you can use that gauge to develop your own numbers compared to a new ring.
FAA certified jet engine and aircraft technician,
Nicholson Speedway class champion 2001,
Yamaha KT100 Service Center,
41 years karting experience