Mine is:
#1 - 125
#2 - 130
#3 - 110
#4 - 80
If compression is low in one or more cylinders, you can isolate the problem to the valves or rings by squirting a little 30 weight motor oil into the cylinder through the spark plug hole and repeating the compression test. The oil temporarily seals the rings. If the readings are higher the second time around, it means the rings and/or cylinder is worn. No change in the compression readings tells you the cylinder has a bad valve.
With electronic testing, a computer analyzer "estimates" compression in each of the engine’s cylinders by measuring slight variations in engine cranking speed. The results correlate well with actual gauge readings and can be completed in a matter of minutes without having to remove any spark plugs. What’s more, the analyzer prints out the results of the compression test making it easy to see and compare the actual numbers.
