GSR15

yesterday i did a compresion test and my compresion was like
Cyl 1- 185
Cyl 2 - 140
Cyl 3 - 120
Cyl 4 - 165

i was like wtf because my car's power seems to be fine or shall i say i think its fine cause it still produces good power. when i took out the spark plugs they were white on the tip i know that its running lean but i have no mods besides a SRI so what could be causing this. also the first compresion test cyl 1 was 220 and then droped to 185 am i doing the compresion test right or wrong??? took out fuse, plugs, spark plugs and steped on the gas when cranking. help plz??