Are the light scratches on the ignition coil from the flywheel making contact?
1. Check the make sure the stator is properly in it's slots on the engine case.
2. Make sure the black ignition coil is securely installed and not sticking out making contact with the flywheel.
3. Make sure there is no contact between the flywheel and case.
If that all fails I'd just take it apart and put it back on again, see if you can find the error that way.
By sputtering I assume you mean the engine turns over without the flywheel on but once it's on the bike it won't turn over.
You're making contact with your flywheel on the stator, coil or case. This shit is frustrating at times I've been there. Rebel Moby is extremely knowledgeable and just trying to help. I've been profiting from him knowledge since I started.
Post a update and message me as well if you'd like. You will figure it out.