new wires for the Mamba Max

sammus - what solder were you using to swap the wires over before you had to return it to castle? does lead-free solder take longer to melt the 60/40? Both times i hardwired my motor, i used 60/40. Now i seen another thread in regards to soldering the MM, one fella said mixing rosin core & lead-free together can cause a cold joint. I will be removing as much old solder from the board as possible. Do you recommend me using rosin core or lead-free for the new wires?

The first time i took the motor wires off the MM, factory soldered w/lead-free solder, they pretty much came off without any dramas, but after hearing some of your horror 'swapping wires' stories, im now a little worried something might go wrong. If worsts comes to worst, i can always either grab a new MM or send the current one to castle...