RE: Assembly of Tettra tank
DT yes you picked the appropriate tank. The bubbless bladder type would be redundant with the pumped system all YS's use. You can use a third line for filling if you want but the plug must be a good tight fit. My preference is to use only two line systems with the feed and pressure line looped just out and right back in the cowel where it is split with a coupler tube. In this way no fueling valve is needed or and extra tank line.
The tanks should not only be wrapped around but also lengthwise. Most important always when fueling a YS unplug the vent/pressure line first, never the feed line until the tank is vented.
This picture shows the feed line loop pulled out on one engine, when flown the loop is just pushed back flush. I don,t own any YS fourstrokes but do use the .45 two strokes that utilize the same pressure system.
John