I use a pipe cleaner dipped in carburetor cleaner for the higher HP fixed jet outboards. It does not damage the metal like welding tip reamers can. For my personal outboards, I install an adjustable needle valve kit. They can then be used at high altitudes without worry. Pipe cleaners used to be available at drug stores, but now are found only at smoke shops. Many hobby shops have them in assorted colors and shapes.
