Jet Powered Kayak Question

Hello. I had a question regarding an equation for thrust. I am thinking about starting a project on converting my Hobie PA14 into a jet powered Kayak so I can maximize the distance covered, go shallower with out worrying about taking the drive unit out. I was thinking about using a 62lb thrust trolling motor for the power source and hook it up to a an impeller. I have a rudder on the kayak so I will probably not be using the turning nozzle, only the reverse bucket. I'm in the early stages of the design and just seeing if it was even practical. I was just curious if there was an equation to see how much thrust/ speed I would be able to get out of the motor if it is hooked up to an impeller and the water going through about a 2" opening with an impeller size being about 4". Here is the link to the trolling motor. http://newportvessels.com/electric-trolling-motor-62lb-thrust-saltwater-l-series/

Kayak info:
13'8"
145 lbs - dry
375 lbs - loaded
beam - 38"

Thank in advance for any helpful information.