I was quite surprised to hear the NS250 has a fuel pump. The carbs are very similar to the NSR250 items, which work perfectly well without a pump, but maybe the height and/or installation angle on the NS necessitates it?! The problem is you could potentially run very lean if they do indeed require greater fuel pressure at higher RPM.

As I said to Wayne, I wish I could be of some help, but just have zero experience with the NS. I'd love to see more content on them though. I hope you stick with it. I might see if I can find a genuine service manual and scan it for the site.
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Andy.
NSR-WORLD.COM

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