This Is really important Im like Flying aerobatic airplanes and as you know arcos do alot of twists and rolls and inverted flight and all that good stuff and when i put a fuel tank together the clunk or fuel pickup does not fall to the front on the plane or where the tube goes in so please give me some solutions I have tried a heavyer clunk...is that the only way to fix in o yea if i get to small of fuel pick up tubing it will kink so what can i do???

10 oz. tank

Replace most of the length of the clunk tubing with a piece of copper or aluminum fuel piping, that will keep the line from folding forward on itself.

I think he's worried about loss of fuel flow frm extended nose-down attitude...

You can 100% cure the possibility... go to a bladder inserted tank and use either a sintered filter clunk, or a perforated brass tube pickup line. The bladder insert goes in, such that the muffler pressure is OUTSIDE the bladder. (see Tetra Tanks ads)

Its easy to make a bladder from a balloon, but you have to replace the balloon every week. (sometimes... every 2 to 3 flights if using more than 10% nitro...) Nitro fuels eat the balloons, just as the fuel residue eats the wing mount rubber bands on trainers.

DuBro and Sullivan tanks... its dfficult. Hayes and GP tanks its easy. Balloon stores have large ones that will just about fill a 10 oz tank without you presurizing th balloon. you loos a bit of tank capacity dueto the balloon not going into the corners very well...

You can also make a hopper tank. It will stay full all of the time.