DLE has constantly made improvements and changes to their engines over the years, there are no official version 1, 2, or 3, etc. engines. About the only thing on a current production 111 thats's the same as the original ones are the bolts that hold it all together. They are all excellent and strong running engines but unless you know the crankshaft has been replaced by someone that knows how to do it, steer clear of low time engines with serial numbers below 650.