I'm not sure, but I think the ASP engines are marketed as Magnum in the US. I've had a couple and, yeah, you can't beat the price on the Magnum. But there are quality control issues. It you get a good one, it's as good as any OS engine. On the other hand, you might also get a dud. One of mine was great. One was pretty hopeless (poor compression, difficult to start, lots of deadsticks). So you pays your money and takes your chances.