Finally I've got around to doing a little bit of work on the bike so here is an update.
I've had this repro exhaust pipe from Asia sitting in a box for about 6 months. See, I bought the pipe from Asia for something like $80 only to find it had no internals. It was too good to be true. So having neither the tools or knowledge to do it I took it all to a local exhaust dude to work on it. It looks great and the bike really revs out now. Sounds more like a 2 stroke too. It now has a power band I can feel. It feels QUICK even.
Here it is with the new (low quality) chrome:
While I was waiting for the pipe I pulled apart the carb and gave it a good clean with carby cleaner. I kept the needle in its current position because I figured it was a touch rich, but with a new pipe that will be less clogged and breath better, it will probably go lean by itself. Logical? To my uneducated newbie ways, sure.
Putting the carb back together was fun. I should have taken photos of the order in which I pulled it apart but after 2 or 3 goes I managed to get all the tangly springs, rods, cables, needles, plungers all as they should be.
I have since cut out a small washer and plugged that choke plunger hole in the carb. Interestingly, after plugging it I had a little bit of trouble starting it (the bike always starts 1st or 2nd kick, hot or cold) so I saw this as the perfect test to find out if the choke has its own hole inside the carb. Pulled the choke and it came to life. This maybe tells me that that hole was definitely not meant to be open like that, and that maybe the easy starting was because the hole was letting air in creating a permanent choke pulled situation.
Now, the news. Bike ran GREAT. Today is a hot 34 degree day so I just took it around the local industrial estate not too far from home and it was good. Except, albeit it taking longer to do it, it still started stuttering so I shut it down and let it cool before taking it home.
So, it looks like it's time to do ignition, points and condenser. I'm tossing up whether to do it myself or not. From the advice you folks have given me it doesn't seem too hard. I do need to find myself the right flywheel puller though.