Are you talking about the 44 tooth sprocket that drives the rear wheel on a happy time frame mounted setup?
You must see both
Bicycle Engine Kit - Sprocket Installation
from Chris Hill
The sprocket installation section is done. It actually doesn't look all that bad. I did the sprocket first because I feel it is the first item that you should install when you are doing your bicycle engine kit. I also did it first because I think it is the hardest and most time consuming part of the installation of these bicycle engine kits. If you can do this part, you've got it made and the rest will be a piece of cake, lol.
and from Thats DAX
supplies online instructions
Info from the pros.