Okay so I have installed my first engine and narrowed down all the problems I had with it to just to a few.. Please help! 1. Clutch is not releasing the back wheel, when I try to pedal before I start the bike it requires a lot of force to get the engine cog to spin. 2. I have not installed the Chain idler, the chain keeps coming off. Do I need to install chain idler? The engine turns on and everything, I just have these two problems, please help!