Today, well yesterday afternoon actually, I decided to attack the C-81. The original fixed jet carb was cleaned up, cleaned out and re-assembled. The float bowl is the correct one as it is the same bowl as the C-120. Difference being the 120 had a gasket which I copied.
Re fitted the cleaned up carb today and started up. Ran a bit better, but the throttle and choke had to be juggled. I wasn't happy with the throttle action. Rather stiff compared to the C-125s. So all that was removed, cleaned up and replaced. Not a lot of difference made.
So back to starting it p and playing with the idle screw. At one point it stopped and refused to re start. This had me a little perplexed. That was until I looked in the petrol tank. I could see the bottom.
Now with fuel in, off we went again. Things are better now but not as I would like. Still can't get a nice smooth idle, but it runs and drives ok at wider throttle openings.
Another thing on the list is a quieter exhaust. This one is a bit too noisy for my liking.