Help with 05 king (carb)

05 king cat 900 carb Just rebuilt the engine from the ground up. Had lost oil feed to the crank when the cable adjuster backed off . Had crank trued and indexed, new pistons rings etc. Got the sled back together ran it for a couple of hours around the house. Seemed to be running good, would load up when idling around, ran good when opened up. Plugs were pretty dark, definetaly not lean. Headed out to the hills, started running on 1 cylinder unless opened up for good stretch. Changed plugs, worked for a short period, now it is only hitting on 1 cylinder again. Was intensified when I busted through a large drift, started backfiring. Has very strong spark. Anyone have similar issues.

Reeds were good when I installed the engine, only has a couple of hours on it. Did have some confusion when reinstalling the power valves. Was not 100% sure if the beveled edge went up or down, installed with the beveled edge up, also noticed that the valves can be adjusted, not sure how to though, the specs or how to measure them.