Some Chain Complications

I have mounted the motor onto the bike and it will run for a short time, but every time i run it something else breaks. For example, i was riding it to test the tension-er was in the correct place and the chain suddenly snapped into a stuck position.

As you can see in the picture, the chain got wedged in between the gear and the actual casing. This could have ended much worse if the engine was running any faster because the chain is actually made of a stronger material than the case its in so if it collided fast enough it would have shattered it. I had to take out the master link in order to get it out of there. The master link is a part of the chain that is removable and can be put back on without having to shatter a link. 

I ended up getting it back into place without assaulting the outer shell, or breaking any links in the chain.