I had been working on a 2013 crf 450 this week. It has a 13.5-1 J&E piston, my 2013 cnc port , my cam and valve springs. This is the RHC 23 mx cam that we also used for dirt track. The first thing we found was that the stock ecu limits the RPMs to 10,800 rpm and seriously hurts the performance for dirt track or SM racing. We also installed a new 50 mm TB and a mototasanari with a modded stack, the ecu was replaced with a vortex ecu. We found the best setting to be #8 the hi comp power map and setting the hi fuel to 9 and the lo and mid to #1 setting lean. We also had vp 110 fuel all the other vortex settings were down 3 hp. We were able to pull 61 hp with this set up and make power flat to 11000 rpm and still reving out to 11700 rpm. This may help any body using my kits and will probally apply to other engines using similar parts on the 2013 and newer bikes.