maybe the choke pulloff? but doubt it. try spraying around the intake to head and see what happens, maybe the intake was milled a bit, mine was loading up a bit and idling rough till i adjusted the piston/rod setup precisely. Not sure about idle circuit my engine is about 400hp and has run low 12's with a holley, Maybe someone that has run a t-quad would know what idle mods need to be done on a very hot big cam motor.