Took the flywheel off a '74 DT250 that I'm restoring.  There was some rust in the case and on the magnets, and the points needed a light sanding.  Got everything cleaned up and now I'm ready to reinstall the flywheel.  How do I make sure that the flywheel is lined up with the key on the shaft?  I kind line it up by eye, but as you go to put the flywheel on, the magnets take over and pull the cover on.  I can't really tell if it's 100% lined up.  I start torquing down on the nut, but it gets pretty tight and I still have a good ways to go before the flywheel is fully seated.  I'm nervous to torque down too hard because I'm not totally sure everything is lined up correctly.

Any tips for ensuring alignment before wrenching down on the shaft nut?

Also, I only have the nut and a split washer.  The service manual mentions a tapered washer but I seem to be missing that.  Is there really anything special about that washer or do I just need a flat washer that fits?
 

I put mine at 12 o’clock slide it in you should be able to see it’s all the way in yes there should be a thick washer    and a lock washer 

So long as crank key is tight in the crank slot then ya can't go wrong. Should just pop on [all the way] & feel its located by a bit of a wiggle/wriggle the tighten up--very tight.

i was forgetting its points ignition so be careful getting past the points heal without catching it.

Yes, you should be able to tell it's on all the way before tightening nut.

Flat washer is hardened. Make sure lock washer hasn't left a burr inside flywheel recess before putting in correct flat washer.

Good tips everyone. Thank you. Found the washer online so I'll acquire that first. Checked the flywheel recess and it seems fine.

If the key is loose in the crank, Loctite it in. Will be far easier to fit the flywheel.

I don't use Loctite. Darn key can be nearly impossible to remove sometimes even without Loctite. I think it was in one of the Yamaha manuals I saw the technique I use if the key is loose enough to fall out... simply use a center punch to put a little dimple on the lower half of the key. Problem solved.

Thanks guys. The key wasn't loose so no problem there. I was able to get the flywheel on, just made double sure I was lined up and it worked out.

Just a tip. Before removing the flywheel get a reference of how much clearance from the flywheel edge to the stator plate? Most likely 1/4” gap. It’s best to use a flashlight if you can to line things up - then spin it counter clockwise a few times loose before adding washers and the fastener.

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