It is supposed to be manufacturers official overbore....and Honda did not do one. I doubt you'd get protested but if you did then AFAIK you would lose if you had +1

Speed is in the head anyways...unless you are within 3 secs of the front then you don;t need the 5 or 10bhp..

Christ.some of the RS125 lads kicked my arse and they didn't have anywhere near 60bhp

Yea get a working bike an been on many a track days at Caldwell and also did a Chris walker race school on a zx6 at Mallory last year where I had the 3rd fastest time from the whole day so got a bit of riding behind me.
The bikes basically got track fairing on it, lights and controls removed, and that is about it!! So that's where I'm at just want to make it into a race bike now. Read about the heads being skimmed but not all that sure how much you can do to the nc's hence why I've asked. Bought zxr400 forks but will now sell after what you said earlier but what about a different rear shock?? Is the total loss route worth going down? Already chopped subframe too!