How do I loosen a muffler for a TT Pro .46 to change the exhaust angle? I tried loosening the thru bolt but the back half just doesn't want to budge. Should I apply some heat to the front half with something like a covering gun? By the way, I love this engine and it's getting a second life on a new airplane, a Tower Razor.

So, often these mufflers have a nut on the back that is just a lock, but also the back half of the muffler is threaded. So the nut on the rear needs to be loosened first(use the screw head in the front to hold the screw...dont try to unscrew from the front. After the nut is loose on the rear, loosen the screw from the front while holding the rear muffler half and it should work. If its stuck from oil you are right on with a bit of heat or light oil(or both) to loosen the gunk. sometimes I tap the screwhead on the front to seperate the halves. Hope this makes sense?

yeah, it makes sense. The screw on the front seems frozen. I'll try some heat, some tapping. Thanks for the fast response.