Yes it looks just like the OS 91 FX but it is different on the inside, the OS is ringed and the Magnum is true ABC. I have never had a warranty issue on any of my engine, I fix them myself if I have a problem. I ordered mine 91 XLS from WWW.peakmodel.com and it cost only 88$, but just some days ago they bumped the price to 108$, still cheap though. From what I have been running this engine it seems to be just as great as the other engines I have from Magnum.