Thanks for video Digger. I don’t have a manual for the Mag 20. And I’m pretty sure the carb on it isn’t original because I thought they didn’t have adjustable ones on them? My Mag 18 doesn’t have an adjustable one
I agree with Steve B. and Jim S. From your problem description, it sounds more like a governor or governor linkage problem rather than a carb problem. First thing I would do is inspect the linkages between the governor and carb throttle connection to make sure everything moves freely and nothing is deformed. Check to make sure the governor spring is in the correct hole on the governor arm. Then I would perform the governor adjustment instructions noted in the Service manual and see if that fixes the problem.
Ok guys, not trying to be thick, but where are you finding a copy of manuals for service? When I open up section on this web site for engine manuals - my screen is blank? So where are you finding them in the web so I can reference the settings for governor linkage?