My first NSR was set up for premix when I got it. Turned out to be a pain and over the winter I replaced the original oil pump items that luckily came with it. Converting to premix on a street bike doesn't do a whole lot for you except make fuel ups irritating!

Sorry it was a bad experience and I hope you get your engine sorted soon. Once you're back up and running it will all be worth it though especially if you reassemble it yourself.

Craig