I believe the factory torque is stamped on the flywheel around the crankshaft hole. Look carefully and I think you’ll find it says “Keep Tight”. If you feel you need a torque value, search for a bolt nut torque chart. It will have a speck for that size and thread pitch. When you have had the flywheel off, after you have run it, you should check the nut to see that it’s still tight or still at the torque spec you used. This is the homemade tool I use.
A "Boathouse Repair" is one thats done without having tools or the skills to do it properly.