I think we should focus on the improved HP ratings after the modifications rather than the actual figures given. The dyno that we (Neal, myself and some others) use in Durban is our benchmark and although it is believed to be reliable, I don't think it is reflecting TRUE REAR WHEEL HORSEPOWER. I found an interesting read here http://www.factorypro.com/dyno/true1.html and find it very difficult to believe that a modified NSR300 or a modified MC21 with NF5 barrels (my bike) could possibly make more "true rear wheel horsepower" than a kitted '98 HONDA RS250. In a previous post I saw that there was mention of an NSR with NF5 barrels (possibly Matt from Tyga's) that made 76HP in the good old US of A. This would be similar to the "not even close to stockish Yam TZ250 00-02".
So with all due respect to all the doctors and gurus out there, I think that horsepower figures should be looked at as an approximate value, not a "mine's bigger than yours" value. At least until everyone in the world uses the same dyno, and that's not going to happen!