the 46fx is an abn motor.. you dont want to run it really really rich. if you cant tell when its 4 stroking.. add a few clicks of throttle trim to cause it to idle a tiny bit faster and you will be able to tell. instead of sounding nice and smooth.. it will sound like its "missing" kind of like when your car isnt running right. that is 4 stroking on these motors. do a search for .46fx and sort thru all the posts and im sure (and i place a dollar on it) that you will find what your looking for!!! or take a look at my website under engine tip page if you still have trouble!! good luck. its a good running motor but you have to have patience with it!!