mine has the twin tanks. are your motors on the centerline of the sponsons? what motors do you have and what size are your mids?

It had 2 1989 200xri's, got rid of them and put on 2 1996 2.5 EFI Offshores on it.( 20"). The motors are lined up with the sponsons. I seen the picture in this thread and thought maybe all single 21 only have one gas tank. Is yours a real twin 21 or has it been converted?

I think it was built as a single from the factory. I want to convert it to a twinn