Attempted to change the water pump today on my 70HP Yamaha motor. Had one bolt that is frozen and still haven;t got it out? Taking it to the airport tomorrow to put a torch on it and soaked it in PB blaster. Never had this issue "BEFORE." Anyone ever had this problem? Never seen a bolt in a lower unit that wouldn;t come out? The other three came out fine. I changed the pump two years ago with no problems. Any suggestions/hints would be helpful.