I have an older black head MDS 46 and it is a great engine. It is powerful, dependable, and easy starting. I run 10%nitro fuel in all my engines with no problem but I understand that the MDS engines were designed to run on lower nitro and don’t like high nitro.

Be sure that it has the latest carburetor (I believe it’s a C-2). I’ve seen some posts regarding occasional problems with the MDS 48 with the old style.