What makes you think it's defective? Is it not starting now or what?

Mate, experience takes time, trial and error. We've all been there and had to go through this learning curve. Some of us with absolutely no outside assistance.

Don't get too frustrated. This is a very fun hobby. You can always ask questions in here, and I'm sure your hobby shop will be happy to help and answer questions for you, if they care about any future possible business from you.

Let us know how you get on.

The first pic is the flywheel, the second is your center spur gear and the third is the clutch bell.

The flywheel is fastened to the engine drive shaft. Turning the fly wheel moves the piston up and down.