oh 100% YES coat the inside and outside, the outside helps and protects the metal, not to mention looks really nice, but the inside is the most important. The inside coating provides a barrier from the flames and heat of the exhaust from going INTO the metal,, it cant help but get hot to some degree but a HUGE difference..
the exhaust heat and residue just slides right out of there without impacting the exhaust pipe metal much at all,
which is what you want.
just as an FYI,, I also restore vintage bikes, and when i rebuild or restore a bike, I keep old exhausts hanging up in my storage area,, we break in the bike and do all the tuning and adjustments on the bike with the crappy old exhaust, Then after 250-500 miles, I install the new pipes,, new chrome. (Triumph, BSA, Nortons)
But what We do is we take the new pipes down and have them ceramic coated just on the ID of the pipes, As a result the pipe temps stay low, and more importantly the Pipes DO NOT turn blue.
I get comments at bike shows and events. "Nice bike, shame he doesnt ride it" My buddy rode his 1940 Triumph Speed twin into the All British field meet, competed against Jags, MGs, Austin Healeys, several thousand cars and 48 bikes that year He TOOK best of show,. He rode it in to the event and rode it out of the event. Some of the Jags were pushed by hand into the judging area. I liked watching the looks on peoples faces...
So that should give you an idea of how much heat it cuts down by ceramic coating,, All Buels would benefit from it, The pipe wrap guys dont see why it just kills their exhaust to INSULATE the heat into the metal.
Ever see those cheap ass BBQ grills that are propane or gas fueled? Notice the burner elements and how they turn to powder after one season.?? Thats the best comparison i can think of.
I hope you can get yours repaired.
