I just purchased a DynoJet kit for my 400EX. DynoJet has a little different jet sizing than others and includes a needle. I was wondering thoughts on jet size for it The instructions are slightly vague and i feel i fit in between stage 1 and 2. My 400ex has a big bore 440 kit, FMF powerbomb header with White Bros. E-series silp on. I have a K&N filter for now but plan on going back to foam.

Also, call me paranoid but I don't want to remove my air lid from fear of crap in engine. (Especially with K&N) Is this a fabricated thought or are there others who feel this way?