HI Derek I think you will have a KMB jet unit in there so to remove the prop take off 4 screws that hold the nozzle on remove motor and coupling and push out the whole shaft it is a snug fit, the shaft runs on a roller bearing you might want to check the condtion of that , the 700bb will run on 14.4 v with no problem , I have a pair of them in my 49 inch Perkasa running on that voltage with out issue for more years than I care to remember
hope this helps for more info on your jet unit check out
http://www.kehrer-modellbau.de/en/
and Happy New Year to all 😀