The problem I found with mine was I tried to hard to really seal the unit up air tight like using weather stripping on the hopper lid seal. adding more silicone sealant to the feed adjuster cleanout plate. It just wasnt designed to be that air tight. the motor is only 70 cfm so its very small so too much drag will only choke the burn. I removed the cast iron panels that house the windows on each side and did seal around the cork gaskets with high temp silicone and also replaced the window gaskets. I get much cleaner burns but still see evidence of an air leak on my door gasket. Regular monthly burnpot removal and vac keeps it going pretty good. Oh and make sure your esp sensor is pushed in all the way and only tighten just slightly more than hand tight. I found after a cleaning I had not pushed it in all the way and the compression ring had slid up the sensor so it felt like it was pushed in when it wasnt.