MK 250WR trans locked up

I just bought a '73 250WR that the former owner had split the cases on several years ago to replace the ignition crank stub (guess why). After he got it all back together, it was locked in gear. He lost heart and never went back into it, finally selling it as-is. The gear lever moves up & down, but doesn't do anything. It feels like it's in 1st gear when you push it with the spark plug out, and there are no odd noises. I'm expecting to open 'er up, but thought I'd ask the collective wisdom on the site if there's anything I should try first.

I think the earlier ones have to be in 3rd gear when assembled.
Some one else will know for sure.

5 speed 3rd gear, 6 speed 4th gear. Make sure if its a 6 speed that the feeder gear is not hitting the case in 1st gear. If it is you will have to dish out the case a little so it will go in gear. The feeder gear has to be in the right spot. 6 gear 1 tooth showing at the bottom and 2 on top. All washers has to be in the right place too. Been there done that.

I would just remove the engine and strip it down laying out everything according to the parts list you can get from Halls. Check here with Picklito as he has an engine within the engine species you are dealing with for disassembly and reassembly requirements. There may be an engine manual for it in Vintage Tech

http://www.halls-cycles.com/default.asp?page=catalogs

This is Picklito's thread, you will find it extremely helpful

http://www.cafehusky.com/threads/1973-400-cr.34913/