Probably a lot haven't learned that it saves a lot time hair pulling time and some the expense for parts.
It like those that don't even use a compression gauge and try go with the finger over the plug hole to test for compression. Here I get borderline compression on two cycle equipment quite a bit. I have learned that if I don't have at least 100 psi I need to be looking at the cylinder condition before spending an hour so trying to get an engine to run when the cylinder is bad. And most 4 cycles here need around 70 psi to start even when a decompression is involved. There are a few exceptions but are few and far in between.
I understand that some don't have the funds to purchase the commercial equipment or are once in a while repairmen but for the professional tech they are invaluable. And I am one of those start-ups on a shoe string budget that took me as few years to budget for my tools; hence, the home made version of the leak down tester. As funds come available I can add the orifice and the second gauge but current setup sure saves time.
Since I got the leak down tester and a compression tester I spend a lot less time troubleshooting problems and more time repairing as I know rather quickly if the engine have internal problems or not.
There is one other tool that very handy to have for 2 cycles especially the handheld here and that is a hand operated vacuum and pressure pump for testing crankcases and carburetors for leaks. This one on my Christmas wish list.
