The plumbing for all YS engines including the .45 and .61 two strokes is the same and the one way check valve must always be in place. This is what allows the tank to build pressure and move the fuel. The exact locations of the pump inlets and the the returns lines will vary from model to model.
The stock check valve which scale for me shows a picture has an arrow and this arrow must point in the proper direction that is show in all the diagrams posted above. This arrow is a little indistinct on the stock one so be careful of the direction its pointing, this is vital.
I beleve central hobbies has aftermarket check valves that are far better marked
After running the tank will always hold pressure for some time so when fulling its best to make sure you releve this pressure by removing the the return line first never the feed line sometime if now it can squirt for six feet or more.
I use to recommend only use Hayes tanks with YS and not the common bung type. Al;so a good practice is to wrap the tank with filament tape to help prevent splitting.
John.