...just with carbs, cams and exhaust from 61hp to 90hp

http://cgi.ebay.de/HONDA-NC-30-VFR-400R ... 3365ecf189

Unless thats got some big ass pistons in there i seriously doubt it, you wont get 90bhp out of 400cc's. I think even the TT-F3 bikes only had 83. Michaels FI bike is the only one i can see breaking the 90bhp barrier but thats a TT-F3 motor i think. Oh and theres the G-force NC which the cost of development on it will make your mind boggle.

5000 euros for fitting a pipe and a HRC carb kit???? i dont think so

That is wishful thinking..

A dyno sheet would be nice eh?