Fellows, many thanks for the inforamtion, it is very helpful. I want to make sure I have explained the problem; I am familiar with the compression bump when you turn an engine over. This is a new engine right out of the box, no plus installed. It actually stops at tdc and there is a small amount of actual play each direction and it seems like you're hitting a wall. if you apply enough force you can turn the engine over and get past the bump or obstruction. I took it from the box and turned it over once and felt this and did it again to be sure and then quit because i didn't want to aggravate the problem. it sounds like this is normal. I own two .tt .46's but never a new one and this belongs to a friend and i didn't want to break it in for him until i thought it was okay to do so. In light of all the answers given, am I ok to start it up you think?