More information might have generated a few more responses.
25.2v at 506 ipm (if thats what you are welding with) seems way to "hot" to me.
Question, why don't you turn it down if its to hot?
The Miller wire machines that I have all have a chart with suggestions for voltage and wire speed located on the machine.
The oldest one is about 15 years old I think. Perhaps your machine is much older and does not have that information attached.
Consider the Miller Welding Calculator as a starting point.
https://www.millerwelds.com/resources/weld-setting-calculators/mig-solid-core-welding-calculatorMaking some assumptions about your situation, the chart would suggest 280 -300 ipm at 18 to 19 volts, 75-25 mix, 0.035 solid wire.
Thats for 1/8" steel. Schedule 10 pipe for the sizes listed are close to 1/8, give or take 0.010 or 0.015".
This setting might work for butt welds, if thats what you are doing.
Welding on fittings such as a weldolet, I can see running hotter.
Floyd