On a old saw I get I will put light machine oil in cyl. Pull it over a couple times and set aside, if piston-cylinder look good. Get it running then see how it runs,idles---- I bought a compression tester years ago--still new in box never had a need for it. Some like to check compression a lot and thats fine with me. I also am into old 1930,40,50, outboards. Have got a lot of old ones up and running. No pressure testing --Just run them and enjoy-My #### are good if it starts --idles runs good.. In all my old outboards I run 8 ounces to a gallon of gas. Dad used a old small green glass coke bottle as a oil measure. Sorta cool I thought. Yall are making me wonder what the pressures are in some of my saws now-may have to dig out the kit LOL!!! ALready got CAD now I have to start check pressure on a few-------------------------------------------------------------------saws David