TN ... I did not mean your statement was related to me, I was just curious, heheheheheee ... you know how many pros there are out there.

Ivan ... I really don't want to say too much here as I am no motor design expert. All I can say is too many people say too much. Everyone seems to be an expert. To be fair the failure may be because its a one off lemon. Things like that happen.

However, a wireman's opinion may not mean much bearing in mind he is not a motor designer. As you say he is a wireman who wires motors. Can you try to further explain what do you mean the shaft is too tight? It sits on bearings. What is touching what and what burnt?

As for the bearing shield, its to ensure that the bearing is shielded against dirt, does not automatically mean no shield is bad, there are bearings which do not use shields and that is good for certain application.

Pertaining to back mounting or more appropriately called radial mount, in theory all outrunners are lousy for back mounting. Hot or cold. That is why they have a C clip and an extra collar to ensure that it does not move that much. Did you use a collar?

All I can say is you made one VERY BIG MISTAKE. Now how are you going to try to claim any warranty? Like I said, it might have been a lemon. Next time, maybe its best to be more patient and not be an eager beaver my friend. Now how will you be able to take that back to the LHS or the manufacturer? Sometimes it pays to be a little more patient.

If you had a BMW Z5 and there was some issue would you take the engine apart on your own to find out why first?