After rebuilding my 400 and breaking in the motor, when i am at full throttle and let out on the throttle my engine will die. I took off my pvt cover and ran it and when I let up the primary came to a dead halt. Is this possible electrical or jetting problem. It has a rcr stage 1 kit on it.

 

Forgot to add it has v-force reeds and a 280 main jet

 

Sounds like your throttle is sticking a little and letting the ETC kill the moter.Pluss the 280 main is a little rich with a reed valve you should have had to drop a jet size to compensate for the added fuel.