I have a 200hp JD engine. Knives are good, anvil is adjusted good, belly plate (I have been under it enough it looks good), engine is operating at full factory setting. I cut a lot of cottonwood, ash, elm and maple. I can only put larger cottonwood into the chipper and smaller other types of wood but if not put into it straight, nothing but problems, the log gets jammed in the corner of the feed opening and the side of the drum. Auto feed only works if it can pull the material into the machine without just spinning and not feeding. I own this machine, I see you sell them, of course they run just fine if you are selling them. I have ran a few other machines, the 280 XP, a cone drum, chuck and ducks and a hydraulic skid loader attachment chipper. 280 was the best, I guess I didn't up grade with the 1890.