So I've got a hitachi carb on my ea81 so my carb or engine not sure let's off a lot of white in the morning when I'm first starting her up. Also once the engine is warmed up it'll do this jerking thing when I hover like the carburetor is choking itself that really slams my transmission and engine which really scares me as I'm currently in a battle of getting the old transmission mounts off to replace them(bolt is In there good). My buddy says it's the lack of back flow I have due to not having a full muffler. Just cat and exhaust. Any thoughts?