All of these things are slightly different.. Some have an adjustable air/fuel mixture, some do not.. Some have springs keeping tension externally on the idle screw, some don't... This video should get you in the ball park.
If you want to go the new carb route, I've been very happy with the couple PZ20 carbs I've purchased. You can grab one at this affiliate link and I may receive a small stipend from Amazon if you purchase from this link or simply go to Amazon and search PZ20. https://www.amazon.com/gp/product/B07NTX9X57/ref=as_li_tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=B07NTX9X57&linkCode=as2&tag=bellyupfish-20&linkId=d0d4f7d0924bd6d0747d97228e40a15f