Thanks @kilo0195 ... I have no problem with chinesse parts or motorbikes, here in Mexico most people runs chinesse bikes, and most mates of my MC run a chinesse bike with more than 7 years and 50K miles

I have found this one:
1993-2017 Mod GN250 update to 300CC GN300 Big Bore 78 MM 18 MM Pin at Sams Store , think is same as yours (the link you provided drives me here to the forum).
Its not expensive, i´m gonna try if it fit into my 2009 :-)
Thanks!