Maintenance Instructions ADJUSTMENTS89Tilt-Up Deck Adjustable StopWhen the carrier frame hinge joint is properly adjust-ed, the deck lock levers should move in and out of theengaged and disengaged positions freely. All fourhitch pins used for height adjustment should sit flushon the washers above the deck pin bushing. On alevel surface, if any pin is sticking up (likely the frontpins), tighten the opposite side or loosen the existingside to lower the pin. Adjustments are made by loos-ening the jam nut and tightening or loosening the setscrews on the Deck Mount Pivot Brackets. Retightenthe jam nut when the adjustment is complete.Tilt-Up Deck Adjustable StopCarburetor - MTThe fixed main jet carburetor is designed to deliverthe correct fuel-to-air mixture to the engine under alloperating conditions. The high idle is set at the fac-tory and cannot be adjusted. The low idle mixturescrew is also set at the factory and normally doesnot need adjustment. The only adjustment normallymade to the carburetor is to set the idle speed.However, if the engine exhibits any of the followingsymptoms, it may be necessary to adjust or servicethe carburetor: black, sooty exhaust smoke; lack ofpower; engine miss or backfire; hard to start; roughrunning; stalls at low idle speed.NOTE: Due to the technical requirements of mod-ern carburetors, refer to the Kohler Service Manualor contact an authorized Kohler engine dealer forcarburetor adjustments and service not described inthis section.Since the carburetor main jet is non-adjustable, foroperation above 5000 ft (1,524 m) above sea level,it may be necessary to change the carburetor mainjet for best fuel economy and power. Contact an au-thorized Kohler dealer to change the carburetormain jet.Engine Idle AdjustmentIMPORTANT: Some emission certified enginesmay not have an adjustable idle mixture needlevalve; it is fixed from the factory and the adjustablescrew is "capped". In this case, only the idle speedis adjustable and only Step 4 of the instructions be-low applies.1. Gently close the idle mixture needle valve byturning it clockwise until it bottoms lightly.IMPORTANT: The needle valve and carburetorseat may be damaged by turning the adjust-ment screw too tight.2. Preliminary Setting: Turn the idle mixture nee-dle valve out (counterclockwise) 1-1/2 turnsfrom the closed position. This initial adjust-ment will allow the engine to be started andwarmed up prior to the final adjustment.CAUTIONDO NOT change the engine governor set-tings or overspeed the engine. The gov-ernor has been factory set for maximumsafe engine operating speed.Set ScrewJam NutCAUTIONALWAYS use the proper engine servicemanual when working on the engine. Un-authorized maintenance operations ormodifications to the engine MAY result inunsafe operating conditions.