Hello,
lately I am rebuilding an FZR400 and wanted to do the oil mod on the bottom cases. Basically the FZR600 and the 400 seem to be shared similar cases but the oil ways on the 400 are somewhat restricted I visited BDK's website and read the comment there but was still a bit unclear. Here are two photos from Rob Bunyan which clear out the issue.

http://img717.imageshack.us/img717/6789/topviewe.jpg

http://img5.imageshack.us/img5/9329/oilgallery.jpg

Regards,

Hi, you have to drill them out to 6mm then helicoil the top of the hole back to an m6 thread so the oil jet can be replaced with a bit of locktight. If you dont replace the oil jet there will be a loss of oil pressure to the crank.