Two important tools you should have is a DMM (Digital Multimeter) and a torque wrench. You can buy a DMM for $5.00 and a torque wrench for $20.00 at Harbor Freight. Look at a garage sale for tools and you can find a torque wrench for less.
You made a comment in your original post about mounting your engine properly in your bike. What did you mean by that? Is your engine not currently mounted correctly? The carburetor should be level as possible.
Here's a couple guides to help in no-start situations:
If you don't have the ability to read Googledocs, here's another guide from the other forum:
Disconnect your kill switch to see if it will start - sometimes they are defective. Also, try staring without the gas cap, as sometimes they are not vented.
Hopefully, you didn't ride it in the rain or leave it sitting in the rain to get wet. This will cause rust to develop on the ignition coil/magneto and cause starting problems.
Make sure the spark plug wire is securely attached to the CDI.
Make sure no bare wires are touching the frame and that all electrical connections are secure.
Last, try to start it with a little starting fluid or a few drops of fuel into the spark plug hole and then put the plug back in and try starting.
Buying parts to see if the problem goes away is an expensive way to problem solve. Buy the proper tools as I mentioned earlier and you'll end up money ahead.