Hi Mike, You will love your new Venus. The kits spinners are cheap junk (I have broken two) so replacement is in order. Don't know about Tetra check values, but if it is the bladder tank my experience is that in an enclosed cowl situation it would be hard to full as you are blind to what is going on. I have read that pylon racers use an exact measurement of fuel to ensure a full tank without being able to see it fill or overflow. I had one on a profile and could see everything.

I recommend Central Hobbies Fuel Dots......hey they are right there in Billings, Montana! Here is a pict. of my Venus with the fuel dot mounted on the right side of the cowl. I have an Irvine.53 with a 11x6 prop, stock fuel tank.

http://www.centralhobbies.com/Fuel/f...ngs/CHFLD.html