Hi all. I just jumped off superminis this year and moved up to the big bike. I know there are threads similar to this all over tt, but there wasn't one that i thought suited my question. Well, i just found a good deal on a lightly used 09 kx250f with 10 hrs on the revuild. Well, its bored 40 over making it a 290. My question is do bbk's change reliability? My dad was always a believer in keeping the stock bore, but now that i've found this bike, and i'm paying for it, i want to know about big bore kits. It also has an aftermarket pipe, if that changes anything.