First, usually a keyway is not wallowed in the crank, as it is quite tuff, but it does happen.
I'd check it first before I'd machine it.
Second: Normally a keyway is cut 90* to the old one, on any shaft, not 180*
That said, there is no reason it has to be that way, as no timing is involved.
But the integrity of the shaft it preserved by going 90*

After I made the post about the keyway on the flywheel end possibly being bad, I realized I should have said the pto end. I'm sorry for causing the confusion. I have yet to remove the pto to look at the problem, have been spraying it everyday with PB Blaster. I hope what someone said about the shaft being okay and it being the sheave that drives the s/g belt. I assume that sheave is available? As always, thanks

Finally got it figered out how to resize the pics, so here they are, better late than never.
Got the pto clutch and drive pulley for the s/g off without any problems. But, just I suspected the keyway is "wallowed" out as well as the shaft being worn from the s/g drive pulley being loose.(see pics) My 1st plan before tearing motor out to cut a keyway is to put one long piece of keystock in keyway. I will try to move everthing ahead on it as far as I can to get away from the bad area of the keyway. I may try to grind the key to fit the taper on the back end of the keyway and put a spot of weld on it to hold it. I'm not quite sure what to do about the shaft being worn down yet. I do'nt know if shim stock will help As you can see from the pic, I have a blown K241AS engine with that pulley on it, but am having trouble getting it off, have tried heat and thats all the farther I got. May have to make some kind of puller, any ideas? Also if you can see from the pics that crank is scored. I'm not sure how bad that is, is that a lot, (can it be repaired by polishing up), will it fit into the K301AS I am working on? Lots of questions, so any and all ideas and info appriciated, thanks agian. Can't seem to gets pics to upload, will try to get them up later.

I had a bad pto keyway in my K321, turned out the rest of the crank was junk too, the machine shop told me they cut them 180 degrees from the old ones. That was what I based my recommendation on, I actually know nothing about cutting a new keyway...lol. I was going to post a pic of my bad one, just as a reference, but I keep getting server errors....I don't think stuff has worked as well after the server update as it did before!

I think your right about server problems. I just posted asking about uploading pics problems. I really wanted you guys to look them over for your input.

I keep getting "server database" error messages from time to time.

There was some downtime last night to update the server. There are still some glitches that are being worked on. :beerchug:

Got the pics working finally, so what do you think about the shaft and crank in other motor

We can't tell if the crank journal is ok or not with a picture; you'll need to clean off the scoring with emery cloth and then mic the journal and compare to the spec in the manual.

Simply put, No. The cranks have different stroke lengths.