X2 on the 27.5 pilot but I was running a 340 like AK when I was pretty much stock I'm currently running a 380 main and its still a little lean at these temps. If I was you I would buy them starting at 300 and I would go up to a 350. Vitos has jets for $2.99 each you could get every thing you need for about $40. I tried the stealership and the only thing that they offered was a whole kit for like $70, but that did come with needles and springs. Pro Circuits like big jets in my experience.