So I got a bit of time tonight after work and borrowed a second compression gauge and pulled all the plugs out ( motor was cold). Everything was 175 - 180 psi in all cylinders. Checked number 2 ( the 90psi with my old gauge Saturday ) and it was fine at 175. Ok, last weekend it was warm from oil change so I started it and let it get warm and checked that one again and still 175 with both gauges. What the heck, maybe my compression gauge is failing and sticky? Super strange. I did mess with idle mixture screws and roughness got a lot better and nearly gone. I guess I will run it a bit longer than do the recommended ten hour valve lash check and redo compression check at that time.

Dont feel bad man.... I pulled out what little hair I had left, filled the neighborhood with various expletives and wasted a ;lot of time trying to figure out why I didnt have power to my dash.... The problem was the bulb in my test light was bad....

Start by throwing old gauge in the trash. Many cheap Chinese gauges are even found on some snap on, Mac, etc. The snap on compression tester and leak down I have always worked flawlessly however it's not necessarily the tool but rather the gauge in many cases. A good gauge can cost more than the compression tester itself. I must say though you had a rather odd experience though. Good tools are priceless but yes can be costly. I used an old craftsman for probably 20 years though that was always right on without false readings. Was rather inexpensive also. Why I changed over to snap on was just because. I love my snap on tools. It's kinda like buying engine parts and accessories. Gets addicting. Lol