Can you describe what your boot looks like? And when did you get it? Does it look like your standard 45 angle diesel engine intake boot that has ribs on it with a reducer in one end or a smooth boot that is sized differently on each end?
I have a 5" to 5" coupler with a 5" to 4" reducer on one side. It is thick rubber. The newer coupler is silicone and has the No Limit label on it.
I think the fact that it is so cold here is what is giving me problems... I am a driveway mechanic not by choice.