You said that you did not replace the needle and seat because it looked fine. I would suggest you either go ahead and replace it or look at the needle with a very strong magnifying glass. I rode Yamaha dirt bikes for many years, and the needles would get a really fine ridge where it sat in the seat. Just enough for the needle to get a little bit dirty and would then stick.
For as inexpensive as a kit costs, it makes sense to eliminate the possibility of it leaving you stuck somewhere and have to make it to the dock on the trolling motor.
Don't ask me how I know that.