Just came across this old Brit pregen review. Concurs almost exactly with my own opinions, which was refreshing, particularly about the 2 strokiness of the engine
http://www.motorcyclespecs.co.za/mod...x250r%2086.htm
I was looking at tests because I always thought mine was around 40 bhp and it ran similar times, in fact slightly better, than my RD400. I had read people talking abysmal outputs for pregens and they didn't seem right. also it will run well into 3 figures not the 97 often given. I know there was a carb size change at some point and a 33hp restricted version for the UK so maybe I'm just lucky.
Anyway here's a nice little ride video by a Kiwi if you haven't seen it yet. Hope it doesn't give the yanks a co-ordination crisis
Link to original page on YouTube.