I have been looking at purchasing what appears to be a well constructed NSR 150 SP. However doing my homework 1st suggests this is not all it appears. That it is a bit of the dark child. Not much support from Japanese companies possibly because they never saw the bike there. The set up now does includ a larger carb, manifold and Tyrga pipe. I haven't seen it or ridden it but I suspect it is still powered closer to a 125cc. I don't think I am gong to spend much time or energy investigating rebuilding, porting, honing if I can't find a larger displacment cylinder kit for it. Is anyone aware of one ? It's charactistics ? How much can the primary cylinder be re- bored out to (saftely) Finally with the great number of other Honda bikes it seems to me that the company would have tried some labor saving techniques and simply adapted this engine to something else any idea of what it might have turned into and if a cylinder from there would easily adapt to the NRS 150. One last question I am under the impression that the 150 and the 125 are different motors not a bigger bore 125 anybody have an opinion on this ? Opinions on hp out put now translated to speed with optimal gear ratio at sea level. Opinion of obtaining streetable 40hp although I did manage to get around NYC, LIE, Hutch, to CT or LI on a way too lean 68cc which stalled at anyless than 7k (ah AH ha ho don't do it if you miss a gear you die.) so I could probably adapt to a spikier powerband but older and wiser now, no just older, and would prefer not javascript:emoticon('')