Generac GP5500 Fuel System Leak Fix !!! Posted 10/1/2012.

Portable Generator, With Type 188F 13hp, 389cc Single Cylinder Engine. Manual or Electric Start. Made in China.
With Huayi Standard of Japan Carburator.

The Consumer Product Safety Commission has received reports of fuel leakage with Generac GP5500 generators. Some reports indicate that fuel started leaking when the generator was new out of the box, while other reports indicate that leaks occurred after the generator was taken out of storage

Carburetor leaks are caused by a float stuck in the lower position. This can be caused by dirty or old fuel, or Ethanol and water mixing in the fuel. Most water in fuel comes from condensation in the tank or fuel can, or by storing generator and fuel outside. In some cases, the problem can be caused by a float that has leaked at the seams, and no longer seals off the flow of fuel into the carburetor.

Models effected include: Buffalo Tools, Centurion by Generac (sold at Lowes), Champion Power Equipment (Product Recalled), Cummins Onan (Product Recalled), Generac, Honeywell (with Generac engine), Honeywell by North Shore Power Systems LLC, Poulan Pro Generators by Husqvarna (Product Recalled), Powerhouse by Northern Tool and Equipment, Steele Porducts, and others equipped with Ruixing, Jing Ke or Huayi Standard of Japan (Huayi Models #: P27-1 or P27-2) carburetors, or similar designed Chinese made carburetors.

The Huayi Carb is used on both electric start and recoil start Generac generators. Generac no longer uses this model in current production products. It has switched to a version that has a plastic choke lever vs the previous style which used a bracket with a round wire handle. You can see the wire choke handle in a video of the fuel leak on the right.

I own a three year old Generac GP 5500 (model 005623-1) with Huayi carb that has this problem. Inspection of the float needle showed it to be made of a bright aluminum alloy, with a synthetic tip. This needle had corrosion and pitting on it’s body, while the synthetic tip had minor wear. Their was no corrosion on the float shaft or needle spring. The needle did not appear to have a plating to protect it from corrosion. I believe the lack of a plating to be the cause of this fuel leak problem.

While trash and debris in the float bowl can cause fuel leaks, I now believe that my fuel leak was caused by a faulty float needle. Corrosion on the needle caused it to stick in the open position and allowed fuel to flow unrestricted into the carburetor.

A big thanks goes out to Bill Cicio In NY, USA, for an excellent picture of how a float needle looks when corroded. He has been working on an Generac GP7500E that has the same fuel leak problem as my GP-5500. View His Picture Here.

Here's How To Fix This.

While internal carburetor parts are not available from Huayi, Jing Ke, Ruixing or the generator manufacturers, parts are available in the US from many small engine parts suppliers. The design is a clone of certain Honda carburetors, used on some models of GX-340 and GX-390 engines. Honda parts or generic equivalents can be used for repairs. See Honda parts manuals for detailed carburetor drawings, or download this PDF and see page 19 for detailed exposed view of this type of carburetor.

Emergency repairs can be made by removing the needle valve, and scraping the ridges along its length with a pocket knife. This should allow the needle to move freely in the carburetor. This repair will be temporary until you can make permeant repairs at a more suitable time. Check the Carburetor Repair page for Repair Tips on how to dissemble these types of carbs.

Use Honda Part #16011-ZA0-931 Float Valve, or equivalent, for all repairs. The Honda part is made of a synthetic polymer not subject to corrosion. The generic parts I tested from Rotary and Stens are made of Aluminum Alloy with a dull finish. This finish may or may not resist corrosion. All samples I tested came with a spring, and were rated for use with E-10 fuel.

This Repair Is Easy.

If you are handy with small engine repair, you can install this part youself in about 30 minuites. Download the Service Bulletin here. It list where to purchase this part, and provides a cross-reference of Generac GP5500 intake gaskets to Honda parts. Also I posted a link on the right to the You Tube video that shows how to repair this fuel leak, and to a web page that shows how to take apart a typical Honda GX390 carb. Picture 4 shows how the needle fits on the float.

If you prefer to have your local small engine dealer install this part, print out this information and take it with you. Because of the cost of dealer service, I recommend that you specify that the Honda part be installed VS the generic parts. The Honda part is made of a synthetic polymer and will not corrode. Replacing an aluminum alloy needle with a synthetic part will prevent this from ever sticking again because of corrosion.

Repair Note 1: The hardest part about this type of carb repair is removing the screws from the Anti-Afterfire Solenoid. The best way is to use a hand impact tool, like the Craftsman Impact Driver. Remove the bit adaptor, and put a socket adapter on it to change the 1/2" square drive to 1/4 square drive. Use a 6 inch extension, and the put a #2 Phillips bit on it. This gives you a straight alignment with the screw. Put the carb in a vice with soft jaws, or two strips of wood, so the vice will not damage the carb. Two or three taps with a 6oz hammer and it's loose without stripping the screws. Tools made by Lisle, like their model 30200 impact driver also work well.

Repair Note 2: While not always needed, replacement carburetor and air filter gaskets should be purchased for this repair. Paper gaskets can stick and tear when you remove them. Gaskets are readily available at many small engine dealers. See my Carburetor Repair page for a more detail listing of replacement gaskets.

Repair Note 3: When purchasing a replacement float needle, always get one with the spring. Some vendors sell them without the spring.

Repair Note 4: When servicing a carburetor that has a fuel leak, replace the in-line fuel filter and fuel line to eliminate any trash the filter has trapped inside its media. If no filter is present, add one of the filters listed in the Service Bulletin.

The Honda Float Valve can be used on many brands of the Chinese made Type 188F 389cc engines.

Long Term Testing.

I am testing a Rotary needle valve on an long term basis in my generator. In August of 2013 I will remove it to see if it has any corrosion, and report back the results on this page.

I plan to test a sample from Stens, and a no name sample that comes in a Chinese carb rebuild kit. This is a long term test plan, and I will post the results here.

This Page Last Updated On 02/08/2014, And Is Current As Of