when the stock points ignition was replaced with the motobecane stock cdi you instantly lost your brake light circuit. what you need to do is get an inexpensive voltage resulator/ rectifier from treatland.tv for under 10 dollars. this particular one has one inlet from the cdi and the far two connectors are 12 volt outlets, one can be used for the headlight and parking light circuits and the other can be used for the brake light circuit. and when you do this, you will need to replace the handlebar brake switches for the ones with the black button also from treatland.tv. good luck and stay well.