Dynojet kit ????s

[MadcapEX]

Are the dynojet sizes and oem jet sizes the same? I got the k&n kit installed the other night and when I went into the carb it had a 148 main jet. Dynojet says to install the 142,this makes no sense,more air smaller jet?? I put the 155 in and their needle in third groove and it seems to run good but I am not sure its not a little rich. Any insight? also the 148 WAS the stock jet.

The Dynojet and the OEM jets do not use the same numbering system. I'm not entirely sure what their relation is, but in my 400EX, I am running the modified airbox with the K&N and a 165 main jet. The thing rocks, but a 165 seems too tall for a stock 400. My next step is to try out the 160 jet. I am also running third notch on the needle.