I wish to confirm my similar observations regarding the Echo CS-590. I have run several CS-590 and CS-600P saws for years, along with the aforementioned modifications. Great saws and a great value. Usually, most Echo saws like this seem to be showing about 165 psi on my compression gauges. One thing that perplexes me, is how Echo keeps producing the type of decompression valves that keep popping up after just one half to one completed pull. Its not that you actually need the decompression valve with just a 60cc saw, but I have rotator cuff problems. I usually don't have this problem with Husqvarna chainsaws, but to be fair, their compression readings are many times a little lower than the Echo. I have the same problem with my Stihl MS-660 magnum, but that brute is putting out over 180 psi compression. Replacement costs for the Echo CS-590 OEM decompression valves are ridiculous compared to aftermarket prices available for Husqvarna. Not only does a good decompression valve save your shoulder, it also spares wear and tear on your recoil starter. Has anybody else experienced this?