There are a few main reasons why leaking fuel during or after priming may occur.

It is possible, but uncommon, to have fuel leak for the following reason:

A new engine, primer and fuel delivery system is most likely working under optimum conditions. This means the engine and fuel system are clean and able to operate at their peak performance levels. Therefore, the primer, if the operator primes a unit properly, may force more than the necessary amount fuel into the carburetor creating an overflow situation. There is no cause for alarm in this situation, just make sure that the leaked fuel evaporates before starting and heating up the engine.

In most cases a fuel leakage situation will be caused by one of the following two reasons:

The first would be that the engine and more specifically the fuel line itself has what is called engine gum or varnish. This varnish situation disallows for proper fuel flow through the fuel delivery system. Since flow is blocked by this debris, fuel fills the accessible areas of the fuel system. These accessible areas have much less of a capacity than the normal fuel delivery system. Therefore a normal prime could easily create an overflow situation in this smaller area if a clog of engine gum does exist. The only good remedy for this is to have someone clean out the fuel system and more specifically the carburetor.

The second situation which usually occurs is dealing with water in the fuel. If the unit has fuel contaminated with water, cold temperatures can cause damage to the fuel system. If a stored unit with water in the gas is forced to withstand freezing temperatures, the water will freeze. Water expands when it freezes, and the ice would squeeze or crush any hollow or weak component. Most often, the carburetor float is what ends up with this damage. A float is what allows the mechanical fuel delivery system to regulate fuel flow. With a crushed float, the carburetor is unable to regulate, and the fuel can overflow from the fuel system. The only repair for this situation is a new float or a new carburetor depending on the extent of the damage.

If one of these situations occurs, there may be a noticeable difficulty in starting and running or may simply be unable to start your unit altogether. Since the quick build up of heat could ignite any spilled or leaked fuel, always remember to wait until this excess fuel is evaporated before attempting to start a unit.

Contact us for more information regarding service to your engine.