OK,so a family member was cleaning out a neighbors garage. He found a 045 Stihl that had been setting for many years. The owner had passed on. Anyway he made an off that was accepted. So, it has great spark and 155 pounds of compression cold.He replaced the gas line and it started right up.So after running it for a bit and it was oiling, he rechecked the compression. Hot it was 125 pounds.It starts and idles fine but the lower numbers have my brother a little shaky. Any suggestions?Is this within acceptable tolerances? Thanks Ken