Did I catch my rig about to burn ?

On the tube that is at the front, just about dead center near the bottom with the 1/4" screw in it, loosen the screw - 1/4" nut driver works best, then move the tube to the left to open up the vent holes until it sounds like a loud jet engine.

Well I am familiar with the sound and have heard it throughout my recent 2 week adventure, I hear it at night mostly when it is quiet. How did it come out

of adjustment and what needs to be adjusted. It's been fine for the last 2 years and my previous rig was 6 years old and I didn't need to do anything to that one.

The plastic/burnt wiring smell is what troubled me.

That is normal for a water heater that isn't adjusted properly, it should sound like a jet engine when it is running, if it is quiet it isn't working properly.