Don't know if it worked yesterday, so here's my Version Ulf Karlson Montesa Cota 247. Just finished it.

Just finished rebuilding. Cota 247 Version Ulf Karlson

Perseverance is a good thing here, plenty of penetrene (much better than WD40 for this), hitting on top of nuts with a drift certainly helps, as does heat directed down through the access holes. You can heat with a controlled torch, then add some candlewax into the top of the nuts, then let it cool ...

Yes, it screws on. I've seen them on eBay, but if you search the Amal site you'll probably only find a smaller diameter one. I don't know if they come with the carb or not, but Amal only list one carb for the 247, so might be worth asking them.

All original Amal - bike is mostly all original, just rebuilt from the ground up.

Got some pictures back from Pete at Inmotion and they showed the hook on the kickstart spring was a slightly different shape to what I had. Modified the spring and it's now together and working, only got the tank to go and I'll be able to fire it up.

Thanks for posting those pictures, I've sent an email to Pete at Inmotion - the hook on my new spring is in line with the pin, so at least 90 degrees "tighter" than yours, although it does look like the one in the parts diagram. Guess I'll wait to hear back from Pete in case I'm missing something ...

Now trying to fit the new kickstart lever return spring. The hook on the spring locates in a notch at the bottom of the lever (as fitted) and the other end of the spring locates in a hole in the casing. Problem is the spring has to be "wound up" about 180 degrees to get the lever in the right ...

I doubt it Rod, the engine appears to have been apart before I got it - actually I'm a bit surprised that was one of the few things I found wrong given the condition of the rest of the bike.
Completed the case repair where it was damaged from kick start over-travel, cleaned up the side of case ...

Finally got it figured out, the parts diagram shows a spacer at each end and as stated the lever end spacer on mine was missing. As it turns out the spacer was assembled between the circlip and the spring, so the circlip was bearing directly on the bush. Best engineering practice suggests there ...