Hello i have a raptor 660 it’s my first one. When i got it it wasn’t starting and the guy i got it from gave me a rectifier and ignition coil and stator with the bike but said the timing was off. I adjusted the timing and adjusted the valves made sure they were in spec and it still wasn’t starting. So i put in the rectifier and ignition coil and stator and it still doesn’t start it will turn over then make a loud pop and my carb comes off it has popped them off twice i don’t know what it could be. i’m also having problems putting the carb on it’s like something is in the way on the left side the right side goes it but the left won’t get past the lip i don’t feel anything in the boot. what should i do about it not starting and the carb?