Thanks for the comments guys. I appreciate it very much.
Bill,
I certainly agree with your obvervations on the sprocket. I experienced the same when I built the Dragon M4A4 2 years ago. I have made some adjustments on this one, too.
On the idler problem, I encountered a problem on that initially. I think it was caused by the wrong part (sort of rectangular plate with 3 bolt heads) attached on the bottom hull which supposedly supports the suspension assembly. I found out that the part mentioned by the instructions is not the correct part as it causes the suspension to be installed a bit higher and not perpendicluar. So I searched and found the correct part which allows the correct positioning of the suspension and giving space between the lower sponson and the idler wheel. I have to remove the said parts and install the correct ones.
Any luck with the tracks?