This section contains only adjustments which apply to an engine tune-up-namely, idle speed and mixture adjustments (on pre-1988 carbureted models). Descriptions of the carburetors/throttle bodies used and complete adjustment procedures can be found in Fuel System .
Idle speed and mixture adjustment is the last step in any tune-up. Prior to making the final carburetor adjustments, make sure that the spark plugs, ignition timing and valve clearance have all been checked, serviced and adjusted (if necessary). If any of these tune-up items have been overlooked, it may be difficult to obtain a proper adjustment.
All adjustments must be made with the engine fully warmed to operating temperatures.