Small Engines (Lawn Mowers, etc.): snow carb., fuel air mixture, mix ratio

Question
Back again. Noticed on my carb (632341)from a previous individual who worked on it that its looks like he left the idle mixture screwj22f2 off. What does this do? Is this why it will periodically rev and then "down rev"? Does the 631029  carb kit include the parts including spring to fix it?

Answer
Are you sure the idle mixture screw is missing?  Usually the engine will not run as the fuel/air mix ratio will be way too rich.

The 631029 kit does contain a new fuel/air needle.

The surging could be caused by a missing fuel/air mixture screw but there could be dirt in the carb as well.

I would order the kit and clean the carb really well.  Did you download the service manual so you know how to install the inlet needles and inlet needle seat?

http://www.smallenginesuppliers.com/html/engine-specs/tecumseh/Tecumseh_L-Head_E

Eric