I tried installing the Rocket cylinder head and nozzle. The cylinder head was too tight for the stock cyma cylinder and it ripped the o rings so went back the original head, loads of silicone grease and the rocket nozzle. With the gun assembled it seems to shoot well again other than the fact that it only shoots auto with the selector in the full auto and semi.
I really don't enjoy the drama that follows every time I open and aeg gearbox. 😔
I'll have to open it up again to see what is preventing it from semi fire.