Yamaha has discontinued the website containing their paper build motorcycles. It was a sad thing but they were able to sustain that website for years. I was able to download the PDFs before but I think I lost them (I haven't checked my external hard drive yet and other laptop). Good news though, some people were able to upload some builds on their own website:

You can head over to the Family Busyness website to get the templates and instructions for these awesome Yamaha paper builds!

Family Busyness Website