The web site of Hanger 9 does not show a Funtana S90 or a Funtana 90 is this an old plane you have? I have the Funtana 100 and know of a 50 and a mini but have not seen a 90. Do you have a pic of the S90? I will look again and see if i just missed it. Sounds cool.

Carmad that is strange I have done lots of ARF"S never a JET one or ducted fan. Seems there would be a place for a fuel tank. But opJose is probabaly correct about this and you might just have to make the fuel tank work and either make a spot or a box of somekind. You might also and this is the way my Super Chipmunk from Nitro was Try silicone. On mine you just set it where it went and siliconed around it. Was very hard to get silicone in there but it did work. Maybe silicone it to the floor.