Rooster is correct. The single motor block is underpowered relative to the trains he wants to run. The second motor block will enable him to run his train his way. The item is on back-order, so he has lots of time to engineer a consistent!
Eric
Eric,
Where did you order it from?
USA Trains. I got the out of stock notification after I paid.
Try …they are USA trains but your not paying for the advertising so usually a little less however they might not have them either. https://charlesro-com.3dcartstores.com/store_r22-115.html
I was just reviewing this thread and forgot the boy snail mailed me his plans for safe keeping. Now that we are getting close to finishing I thought I would post his plans. May I also say that he is “right on track” and it actually brought a tear to my eye and still does!
Looks spot on so far young man!
Mr. 
Shut Up John Bouck 
This child is all mine to corrupt!