Wasn't there a source of new/remanufactured kits? And someone was fitting them to late model YZF frames? Or did I imagine it?
Is the kit fundamentally flawed, or is it just a matter of tweaking the porting/head/whatever to get them right?
The short stroke/big bore combination will surely limit it's potential compared to a properly designed motor, but you'd think that it would still be able to out-perform a 250 if the rest of it was right.