check engine light

Hi i recently got a 2015 switchback with the most blown up motor i had ever seen. I got a new motor and rebuilt it then swapped it for the blown up one. After breaking it in the only problem i seem to have is that at full throttle the check engine light will pop on and the throttle will cut out...

I am hoping someone can help, I have 2009 Assault that has a problem of check engine light coming on solid along with engine stall and or a miss, low power, if you shut off it can be good for a few miles and then do it again, took to dealer to have codes read and told me it had codes for voltage...

08 D7 Had an electrical code tripping my check engine light and traced it down to some bad wires in the magneto. Replaced the magneto and still have the same check engine light flashing. Is there a way to rest that light? Pretty confident that I fix my problem. Thanks