You cannot officially import any used vehicle into Brazil, just not allowed unfortunately.
Only new vehicles can be imported, but count on about 100% import duties.
If you do want to get yor bike to Brazil, the way to go is overland. NEVER try to get it there through a brazilian port.
Ship it instead to eg Buenos Aires and drive to Foz do Iguazu. No questions asked, no one will even stop you at the border, you have to get off the bike and go after customs if you feel like it..
Just beware that there is a customs checkpoint between Foz and Cascavel.
But there is a detour you can take to avoid it.
Or on sundays it is closed....
If you have a british paspoort though (or any other non brazilian) you can ofcourse always drive around as a tourist.