My 125 wr 1978 wont start

yes, you should flood the carb till it runs out onto the cases....

The fact that you got it started by towing it combined with a lot of rattling tells me compression may be low. You may need to replace the top end. Kick starting a motorcycle turns the motor over slower than when towing it. You may not be getting enough compression when using the kicking starter. In addition to a lack of compression the motor will also experience a lack of vacuum, which is needed to make the carb work properly.