Smithsonian Motor-Works

SOME reviewers have gotten this to work. But as other reviewers have stated... this model is "challenging." Especially when your son's hopes are so pumped up, he's so excited to get working on it. Then you realize the following problems:- There is no way an 8 or 9 year old is building this- screws are *extremely* difficult to install. I'd use a power tool, but I'm sure I'd just wreck the plastic- so many places for pieces to bind up- instructions are NOT clear in at least 2 places - installation of the cam shaft and the rockers. Make a mistake here and you'll be doing a partial engine-rebuild to flip things around.- gears are plastic - if anything inside binds up and keeps the works from turning, the motor will spin away and grind down the teeth on the gear.- one of the electrical ports on the battery pack was dead. there's no way to open this up to repair unless you're confident of your abilities to fabricate new plastic parts. so we can now either plug in the motor or the spark plug lights, not both.This kit is SO challenging my son lost interest within a few minutes - his participation was limited to placing the screws, finding the parts... and then this is completely destroyed when the motor doesn't work as expected.I estimated to my wife that this motor would run a week and then die due to failure of the plastic parts. But it didn't even make a full minute before things went south.This was Christmas present and so now almost 10 months later, I'm sure there's no way to get a refund - I'm not even interested in a replacement, I don't think my fingers can take the torture of screwing in anymore screws.Buyer beware!