Just to let everyone know moisture in the fuel was the problem. Thanks Ken. Good info from everyone. I do plan on giving it a good flush and make sure it is tuned. finally had a good day at the field. The tiger engine in the arrow ran as good as every. But after flying my p-51 its right gear collapsed on the first landing so back to the hanger for some A/R work. I tell you there is more in fixing and maintaning these thing's than flying, but I guess that is the nature of the beast. Thanks for the inputs.