Yes. It is a pressure/vac test of the crankcase. This involves blocking off the intake port, exhaust port, and if present the impulse port for the carburetor. You then test though the spark plug hole; unless you have the specialize block off plates that have port for doing this. Here I use hard rubber to cover the intake and exhaust port while tightening down the carburetor and muffler then I use a modified plug adapter in place of the regular plug. Basically it is a hollow out spark plug with fitting for attaching the hose of tester to.
My tester is a MityVac 8500 but any low pressure tester with gauge will work. If pressure leak indicated then soapy water can to determine where the leak is. Note seals can leak both ways or just one way which why you do both the vacuum and pressure tests. On the vacuum test you pull a 0.5 Bar (7.25 psi) vacuum and if it holds a minimum of 0.3 bar (4.3 psi) vacuum then the system is good otherwise you have a leak. It same for pressure as use 0.5 bar (7.25 psi) pressure. If it drops below 0.3 bar (4.3 psi) then you have a leak. Good thing gauges normally have multiple pressure scales as I am use to inches of mercury for vacuum readings.
Plus like any 2 cycle these saws can be troublesome to troubleshoot even they are some simplest designs as everything must be right. But once you get the experience working on them becomes second nature to troubleshoot them as develop a test procedure that works best for you. If you hung up just set it aside until your mind fog clears.
Hopefully I not too confusing on this.
