I’m running them at those settings because that’s the only setting they will run at.I have the low speed set at 1 1/2 out and high speed 3/4.Starts and back fires and runs rough.I open low speed another turn,it quits backfiring,but still runs rough.Nothing I do with High speed while it’s running has any effect.Both motors act the same.I am using the same pressure tank for both.If there was an issue with the tank,would that explain it.
