I am reaching out, 550 will idle but will not run when throttle is used. Had code 12 on display, dealer replaced starter. It starts and idles but will not go. Talked to dealers mech. and he said all he did was replace starter. Has no great ideas as to what it could be. Not very knowledgeable about ATVs. I changed the spark plug and it revved up. Oh boy easy fix!! Went 40 feet and it goes back to falling on its face. So has anybody had the same problem out there? 2013 Grizzly 550 EFI and it has 144 hours with 1050 miles.