I bought it about mid 2007 but mine from Hong Kong could have been old stock or rejects or something, if you got yours in the US it is probibly OK. I will confirm and document any changes to the inside of the engine when I receive my new parts but I would not get to worryed about it as if your engine is out of warinty and as long as we can get parts they are quite cheap and no more complicated than a glow engine inside you can have a new engine inside for around $100, thats new crank, bearings,connecting rod, piston, ring, gasket set, the conecting rod with big end bearing and conecting rod all come as one part so if the big end bearing goes as mine did you replace the hole crank assembly not just the bearing this hole assembly cost me A$44 . and mine may be the first and only one for this to happon to. As Bob said if it developes exesive play when you rock the prop back and forth (Mine was a good 10 - 15 degrees of slope at any angle) at all 360 digree positions not just at top dead centure as some play here can be normal - my engine was very evident that something was rong and really ratily then stop using the engine or you will have a majour falure shortly after. I hope I have not got every body parinode about there engines, honistly it will stick out like Dogs balls if you get this problem so if you are not really sure then the engine is probibly OK, a few people new something was wrong with my engine by the way it sounded, thats how noticible it was both on the ground and in the air. Go fly and have fun.