I do not think Changfa is ever going to get EPA certifications. I'm told by Changfa that this is not a plan. This is a 3rd world engine and Changfa sells a lot more engines in China and other Asian countries that they could ever sell to the average buy-and-throw-away consumers in America. They are not going to spend thousands making this KISS engine an electro-technologic gizmo only for the few slow-speed aficionados of us. Even VW stopped producing the 2006 Golf/Jetta diesel engines because it needed a major redesign to comply with 2007 new EPA regualtions. China has other diesel engines that seem to have a wider market in America like the 385, 395, 495 as found in generators and Jinma tractors. Of course, these are EPA certified; the market for typical hobby farm boomers wanting tractors and generators is bigger than the one for people like us looking for cheap/fun power! Just my two cents.
BTW, I agree that the engine mounted radiators are not as bad as we think. I sell more and more. It makes the engine a little more Plug-And-Play-And-...Forget. No wonder why the water seal ring is the number one selling part, people just forget to add water in the hopper.
Pat