Hi cheese_puddin
One problem I see is that the nut being tight is a relative term. What is very tight? For years I used the small cross wrench that is used to tighten the glow plug and the prop nut. I would tighten the prop nut "very tight". Occasionally the starter would turn the nut off. Now I use an adjustable 8" wrench. To get a feel for what to do I first used the old cross wrench and tightened the nut "very tight". I then used the longer wrench and tightened the nut "more". I have never loosend the nut again with the electric starter.