Protecting Your Generator Against Fuel Varnishing

What Happens
If you store your RV over the winter or don't operate it often enough to refuel the gas tank every month, you could develop a fuel varnishing problem in your generator engine. Fuel varnishing is a gummy residue that clogs the generator carburetor and fuel pump. It's caused by the deterioration of fuel that sits in the engine too long. Fuel varnishing affects many engines but it's more noticeable in generators because the engines are smaller and sensitive to fuel issues. Even the slightest decrease in efficiency has a big impact on performance. A generator with varnish buildup may start but run like it needs a tune-up.

Preventing It
The only ways to prevent fuel varnishing is to treat the contents of the tank supplying fuel to the generator with a fuel preservative and to exercise the set. We recommend using a fuel stabilizer, especially on infrequently used RVs. Emptying the tank won't prevent fuel varnishing because a small amount of fuel always remains in the generator carburetor. If you plan to leave the tank empty, we recommend that you add a special mixture of fuel and a preservative before you run the tank dry so the residual fuel contains the preservative. Fuel stabilizer may be purchased at any auto parts store.

What if it's too late?
Once varnishing has occurred, adding a preservative won't correct the problem. You need to add a fuel cleaner and manually scrub the varnish from the fuel system parts. Worst case (we need to do this a lot!), you may need to replace the carburetor.

In Conclusion
By understanding how to properly care for your RV generator and protect against fuel varnishing, you'll enjoy better performance and longer, service-free operation. It may seem strange that NOT using a product causes it to fail faster. With generators, that's exactly the case. Run your generator at LEAST once per month for an hour or so to keep it healthy.