I'm having trouble getting the prop nut tight. When I turn the nut the prop spins counter clockwise. Obviously the locaton of the prop is imprtant when using a spinner so that it aligns with the holes. What am I doing wrong?

I just old the prop and the back of the spinner in one hand and tighten with the other. That way I can hold the position until it's right enough to catch. I don't make my prop nuts really tight beause I don't want to strip anything, but I don't want them to come apart either so I use a little blue locktight.

You need to be tightening the prop nut as tight as possible. The shaft is made of an extremely tough steel--you're not going to strip it using ordinary hand tools and a generous amount of pressure. I'm big, and I tighten the nut as tight as I physically can with a wrench, and have never stripped anything. Think about the stress the crankshaft undergoes when it's turning 13000 RPM--you're not going to hurt it with your wrench. If anything, you'll strip the nut first, but, as I've said, I've never been able to do that. If you throw the prop, you're likely to be saying good bye to that engine--if you don't catch it in time and throttle back, the thing will literally fly apart on you in the air.

Perhaps I should define "really tight" as plenty tight enough (especially with lock tight) but not as tight as I can make it. I have broken lots of bolts in my day so I go easy on stuff. If I want it to stay together I just put some locktight on it. Also, your right about the crankshaft having lots of vibration and rotational stress while running (which the lock tight is designed to address), but the stress you put on something pressing together is completely different. How often have you heard of a lug nut fail due to rotational forces vs over tightening? Also, don't under-estimate how much force you can put on something. Once I broke off a 5/16 bolt in the clutch on my snowmobile with a hand wrench and I'm not a very big guy.

Cut two disks of sandpaper about 1 inch in diameter and glue them paper to paper side. Cut a hole in the center of this the size of your crankshaft. Put this sandpaper disk between the spinner backplate and the prop hub. Now you can tighten the nut down without the prop or backplate slipping. Works for me every time.

I usually bear down pretty hard with a mid-sized adjustable wrench when I tighten the nut. The only one I ever stripped out was a brass heavy hub. Good luck!

It should be as tight as you can "make it." If not, you are working on borowed time. Lock tight will not hold up under the heat and stress the crank will put it through. Being as tight as you can get it will usually do the trick.