What should the fuel adjustment needle of the carburetor be set to?
A. Always make sure that you have exhausted all other possible options before attempting to tamper with the carburetor settings. Click here to see a list of other possible problems before tampering with the carburetor. All electric start thermal fog machines have been produced after 1987. These carburetors require a slightly different setting than the carburetor used on the pre-1987 version “hand pump start” foggers. For all “electric start” (all are equipped with a push button switch for air and ignition) thermal foggers except the Mistermax Model 2640, the screw should be set to -5/8 of a turn open. The Mistermax Model 2640 is equipped with two needle screws. The HIGH screw should be set to 1-1/2 turns open, and the LOW should be set to 2 turns open. These settings tend to vary depending on climate, temperature, altitude etc. The ideal carburetor setting is the one that enables the engine to produce the highest pressure. To achieve best results, it is recommended that a manometer or
