Well, the issue with pressure testing Stihl saws is that the intake system can't be off, so it has to be done while built, which at times makes it a pain to see the leak location. Anyway, you need a pressure tester and blanking plates for the intake and muffler. If you are gonna work on saws you need those tools in your arsenal. Process is easy. If it is leaking, your just gonna toast it again. I personally never rebuild saws that small...just not worth it. But then, I do it for customers, not myself!