Although many things can cause your tractor to idle incorrectly, there are three passages in the carburetor that most often will not let your tractor idle well. The three passages (#1, #2, and #3) shown in the diagram are 90% of the carburetor idle problems that show up on my bench. These passages can not be cleaned out with a wire or soaked. We are dealing with rust, not old fuel. A #40 6 inch aircraft drill bit * is needed to run through passages #1 and #2. The #53 drill bit is needed for passage #3. These drill bits will take the passages back to their original size. The #1 passage is located through the front of the carburetor (manifold side) and is the top 10 x 32 drill plug. The lower drill plug of the two is a 12 x 32. The #2 passage is located in front of the idle adjust screw. The #3 secret passage is located in the bottom of the carburetor stem and across from the idle needle tip. You will need to remove the drill plugs to do this procedure. Remove all the drill plugs and check all the passages when overhauling your carburetor.
Note: To ease removal, apply heat directly to the drill plugs for a couple of seconds. Allow the drill plugs to cool before trying to remove.
* To order drill bits consult our Tools page for more information.
