Front Sprocket Nut

I have an 81 xs650 that has been leaking oil because the front sprocket nut was not tight enough and there was some wiggle room between the sprocket and nut. After trying to tighten the nut manually with no success I decided to try an impact wrench. At first the impact wrench could not get the nut to move at all, after it finally did I believe that it stripped it. The nut spins both ways but does not tighten or loosen. Luckily the chain and sprocket are basically brand new. Has anybody had this problem before? How do I fix it when the time comes for a new chain? And is it safe to ride? Also after a short ride it doesnt look like it is leaking oil.

The nut is cut out on one side and that side should face in. The splines on the countershaft stick out slightly past the sprocket for the teeth on the lock washer to grab onto. The cut-out on the nut swallows that so the outer portion of the nut can bear against the sprocket and make it tight.

You better hope the nut stripped and not the threads on the countershaft. I would replace the nut. No telling if it will fall off while riding. With the sprocket loose on the shaft, you should have a bad oil leak. If you don't, you better check your oil, lol.

You'll have to remove the nut, light back pressure from a pry bar while using an air gun, and order a new one. Make sure the threads on the countershaft aren't damaged. If they are you can try cleaning them up with a thread file. When reinstalling I like to dab some Loctite CA-5 #51007 on the splines. Helps for future removal and prevents shaft wear etc.
I think, of the top of my head, the nut should be set at 65ftlbs. Which isn't a lot and an air gun isn't a solid idea on install.

I appreciate the responses and I have already ordered a new nut. Any ideas on why it stripped?

Did you have it on backwards? If so, it would bottom out against the splines before the sprocket got tight. Another possibility is if you've done a 520 chain and sprocket conversion. Those sprockets are thinner and some require a shim washer.

I'm just about positive it is on correctly. I will check this weekend when I get some time. If it does need a shim would I just use any washer that fits? I am almost positive I stayed with the 530 but maybe I screwed up and ordered the 520 front sprocket

It stripped because you used an impact wrench to tighten it. I tighten the nut with a socket on my torque wrench. I have a helper set on the bike and have them hold the rear brake. If no helper I use a piece of pipe or so0meb thing similar through the wheel. then as you tighten the nut the rear wheel turns till the pipe stops against the swing arm.
Leo

I tried that exact method. Even tried using some leverage, couldn't get it to budge at all