Some builders don’t hone the bore right. I’ve seen guys that just scratch it with a big spring loaded brake hone with no torque plates, don’t even measure and call it done. Loose as a goose because, as long as it doesn’t stick the piston they did a perfect job.
That being said, let us know what reading you get when you check it with open throttle.
FAA certified jet engine and aircraft technician,
Nicholson Speedway class champion 2001,
Yamaha KT100 Service Center,
41 years karting experience