How to Hook an HHO Generator to a Carburetor

Written by eli laurens
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An older automobile with a carburettor can be modified to use HHO gas, or oxyhydrogen. Without a computer, there is no need for EFIE (electronic fuel injection enhancer) devices, but the installer will need to adjust the mechanical mixture settings on the carburettor to a leaner condition. The average backyard mechanic can hook up an HHO device to a carburettor in about 30 minutes.

Skill level:

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Things you need

  • 1/4-inch fuel hose, about 4 feet long
  • 10-gauge insulated wire (about 20 feet)
  • Electrical tape
  • Minimum of two hose clamps or zip ties

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  1. 1

    Secure the generator into the engine compartment that allows for hose and electrical connections. The generator, typically a cylinder, can be wedged into cool, dry areas of the engine compartment. Older, carburetted autos have more engine room than modern vehicles, and can accommodate several generators connected in series (the output of one generator goes to the input of the next, ending at the carburettor).

  2. 2

    Determine the best entry point for the HHO gas by examining the carburettor. If the carbuetor is a stock model, the HHO gas can be routed through the air intake hose before or after the air filter. Cut a small hole in the side of the air intake hose and run the HHO output line up into it, keeping the line pointed in the direction of the air flow (creates vacuum). For many aftermarket carburettors, there is a service port vacuum that works perfectly for HHO gas introduction. This service port is usually on the front of the carburettor with a stopper cover on it. Remove the cover and attach the output of the HHO generator to the nozzle. Secure the hose with a hose clamp or zip tie. The running carburettor will draw HHO gas directly into the venturi, and mix with the gasoline simultaneously with incoming air.

  3. 3

    Adjust the carburettor's mechanical mixture settings toward a "lean" condition. There are typically one or two idle mixture screws on the front or sides of a carburettor; turning these screws clockwise will lean the mixture. On two-screw types, keep the screws synchronised. There is also an adjustment screw for setting the idle speed, turning it clockwise will raise the idle and counterclockwise will lower it. It will not be necessary to adjust the timing of the ignition system unless the mixture settings are changed dramatically. Some carburettors will have "metering rods" that can be removed and replaced with differing tapers, longer tapers giving a lean condition at cruising speeds. Replace these rods by turning the No. 6 hex head screw on each side of the front barrels of the carburettor counterclockwise, and removing the plate holding the rods down. Each rod has a spring, and these springs tend to jump out if not handled carefully. Take the spring from the old rod, insert it into the new rod, and replace the assembly back into the covered hole. Position the cover plate and turn the screw clockwise to lock it down.

  4. 4

    Wire the negative terminal of the HHO generator to a good body ground by looping the wire around a body bolt and turning it clockwise. Attach the positive terminal wire to an ignition-only hot wire with an in-line fuse for added protection. Wrap all connections with a liberal amount of electrical tape. When the ignition is on, the generator will produce gas. Routed to the intake or vacuum port of the carburettor, the HHO gas is constantly sucked out of the generator and into the engine.

Tips and warnings

  • Use an air filter on the open end of the HHO generator so that dirt and debris do not enter the generator chamber.
  • Use a flashback arrester and "bubbler" tank for added backfire protection.
  • Use extreme caution when working around fuels and engines.

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