Agreed.....They are a rough idler,and a decarb may make it worse. Also you will probably need to reset everything again. It looks as though youve done a good job of getting the best out of a tired old engine. Id be happy you dont need to rebuild it for now.
If its just a bit shaky and tinny at idle,but smooth through the throttle range,then you wont get much better... Your call if you want to play around and learn, and also how far you really want to go for a perfect runner, which in my opinion is unachievable. They are Just naturally a rough old machine.
