Porter
Junior Member
I agree that killing the rear cylinder won't buy you much extra time. I use it more as an indicator to make me aware of the situation. If heat mode kicks in, and I clearly see I won't be moving any time soon, it tells me that I need to make some kind of decision. My heat mode kicks in when the temp sensor (mounted in Front cylinder) hits about 310*. Killing the rear cylinder does not stop the heat from rising. Extra fuel can only do so much. On a normal day, my air fuel ratio at idle is about 13.2- 13.4. I have not measured it, but when heat mode kicks in, I am sure the front mixture goings into the low 12's maybe even in the 11's. Trust me it is rich, and the temp still rises. These engines are air cooled, not ambient cooled. Unless there is air flow around the fins, the temp will continue to rise. When exhaust gases are 950*, there is no stopping it.
I have experienced (not with HD engines but with other air cooled engines) needless engine damage caused by excessive (uncontrolled) engine temperatures. At the very least I have seen piston rings de-tension or loose spring tension which results in compression lose and oil control. Not seeing an engine seize does not mean your engine escaped damage. Who's going to really notice a small amount of compression lose or a little more oil usage. I also feel that if you don't have a current 96 or 103, you have a lot less to worry about as far as heat goes.
I concur. I had the HM turned on simply to be an indicator to make a decision.
One thought about the post on the "hot/cold" plugs: I remember reading that HD spark plugs are a precise item on new models (2007 on???) in that an error code can be thrown.