How to Reduce the Fuel Pressure in a Carby Robert Bayly
Vehicles that use a carburetor sometimes suffer from too much fuel pump pressure. This causes fuel to be pushed past the needle and seat assembly in the carburetor, which leads to flooding. The needle and seat work with the fuel bowl float in much the same way your toilet works. The fuel bowl fills with fuel. The float rises, and at a set point pushes the needle valve into the seat, cutting off the fuel flow. You can fix the problem by Installing a pressure regulator.
Locate the rubber fuel hose that runs from the fuel pump to the carburetor. Find a safe spot along the hose where you can install the regulator. Cut the fuel hose with a razor blade at this spot.
Install the proper size hose fittings in each end of the pressure regulator. They will be in the kit.
Place a hose clamp over each end of the fuel hose. Push the hose ends onto the fittings on the regulator. Be sure to note the flow direction indicated by an arrow on the regulator. The arrow points towards the carburetor.
Tighten the hose clamps. Set the regulator for two pounds of pressure by pushing down on the knob in the center of the regulator and turning the pointer to the number "2." Start the vehicle and check for leaks.
Test drive the vehicle to make sure there is adequate pressure to run it on the road. If the vehicle hesitates or stalls, increase the pressure by 1/2-pound until it doesn't hesitate.
Things You'll Need
- Razor blade
- Flat screwdriver
- Fuel pressure regulator kit
Robert Bayly, based in Apple Valley, California, began writing in 2010, his "how to" articles can be found on eHow. With more than 15 years in the auto industry, Bayly has been an auto and diesel mechanic, service writer and parts manager. He received certificates from Pontiac (parts system), Cat Diesel (engine service), Saab and Fiat (parts- warranty system).