That is not too bad for an O scale loco. I would check the speed. If it is OK, My opinion stick with them.
The Weaver locos came with Pittman 8314 motors, I think, and they draw over 2 amps under heavy load. The safe thing if using DCC is to use an NCE D408SR decoder. These are rated at 4 amps continuous and the latest release is 10 amps stall. They have really great motor control and I think 7-8 lighting or other function outputs.