Originally Posted By: Vikas
Tucumseh 9hp, Sears 28". I wish I could figure why it will die very slowly (like 30-60 seconds) if I leave it on slow idle. It is annoying to leave it on high idle when I need to use the shovel. Since I am used to electric start inside garage, I am not going to let it stall on me in the middle of driveway. I have pull-started only once just to see if I can do it. I have thrown Techron and Regane dosage at it but I don't think it is fixing that particular symptom.
Clogged idle air passageway, or dried out black O ring gasket for the bowl.
The idle air passageway air input is a very small hole on the floor of the air passageway just behind the choke plate.
Remove the idle screw to blow out the idle air circuit with a spray can of gum-out using the straw connected to the can. When you put the idle screw back in:
If the idle air screw has a black plastic cap it is not adjustable, and you just put it in all the way and put the black plastic cap back on.
If the idle air screw has no black plastic cap it is adjustable, and after you clean the idle air circuit you have to adjust to the middle of it running well. Ie, find how far in you can turn it until it runs rough because it is too lean. Then find how far out you can turn it until it runs rough from being too rich. And put it in the middle of those two.
After you get it running good by cleaning out the idle air passageway, when you put it away for summer storage, it would be a good idea to drain the carb bowl and blast some WD-40 through those passageway via the holes exposed when the carb bowl is off, and by way of the little hole on the floor of the air passageway.