These cases are setup for the Homelite pyramid reed system Problem is that all the parts are obsolete and not available from Homelite. I found a guy who has these parts in limited supply. There are 5 part numbers that make up one reed assembly, sans the petals. Boyeson has these or will make them. I have 3 assemblies for my 61cc twins and will be getting more for these smaller twins. I will be getting some as spare parts just in case as these things are on the bottom of the engine. Whever is interested in these parts let me know. The guy is digging up the parts and will be calling me back to let me know how many complete assemblies he can put together. There are some other reed assemblies that may work. Echo has some in current saws but they are 30 to 33cc. Don't know how they would work here. My guess is they will be fine. Other than that you may need to machine an adapter to mate to the case.