The wire/coil colors make it a phase maker ignition and kill switch has to be closed to run. Also the colors are not in correct location. Need to pull flywheel and see what wires wwhere repaired
Leave the plate on and set cavitation plate about 1" below pad. Is it a EFI ? Could be a injector or ignition problem. If a carb model 4S could have a carb problem
The primer does not have a diaphragm inside, it is a one-way valve. It uses pressure from the primer bulb and fuel pump to squirt fuel into intake when activated