Fix poor or non-running engines with 4 oz. Mechanic in a Bottle. This synthetic fuel additive works in your power equipment with 2-cycle and 4-cycle engines. It removes all varnish in the fuel system without having to remove the carburetor, removes carbon deposits, removes water, reconditions rubber and plastic components and revitalizes old fuel. Mechanic in a Bottle rejuvenates your equipment's fuel system so that it starts efficiently and operates in top condition. Treats up to 40 gal 2-cycle or 4-cycle engines Quickly fix engines without removing the carburetor, avoiding costly repairs Reconditions rubber and plastic components and rejuvenates rubber gaskets that may have dried out from ethanol to keep engine in top working condition, avoiding repairs and down time Removes water that causes corrosion and poor running Restores old, decayed fuel by breaking down carbon deposits and adding an octane booster to replace lost octane