The threads on my plastic prop nut that secures my MG TM prop to the motor shaft is stripped out. So, I need to buy a stopnut at the Hardware store to jerry-rig it until I get an actual replacement prop nut from online. Does anyone happen to know what size stop nut I need to get in order to fit properly on the motor shaft of my TM? I don't have my boat with me and I was hoping get a nut during my lunch break today. The model is a Motorguide 782 Tour edition 82# thrust.