Suburban SW6D Help!

Ok, Back home after a week of military style showers,drained hw heater and looked as best i could, I can see the cold water inlet and dip tube which appears to be fine although it looks to be natural translucent polyethylene rather than black. Tried every which way to see the hot water outlet but could not get the angle to view it and my inspection mirror was just a hair too big to fit through the opening. I did not see anything lying in the bottom of the tank. I haven't checked the temp of the water as suggested but it seemed plenty hot just wouldn't stay that way. It did seem to take a bit longer than I thought it should to kick on while the hot water is being used, I'm wondering if the thermostat could be the culprit not allowing the heater to kick on until too deep into the cycle for it to recover. (I know it won't actually recover just prolong the inevitable). If shut off is set at 130 degrees what should kick on temp be?