Repair 7

Walbro Carburetor Adjust Tools

Carburetors combine fuel and air for internal combustion engines. Walbro carburetors are generally used for hand-held devices such as line-trimmers, chainsaws and leaf blowers. The tools used to adjust Walbro carburetors are not available to the general public from Walbro or Walbro warehouse distribution centers due to recent EPA and California Air Resources Board emissions regulations. The carburetors that these tools are used to adjust are emission-regulated carburetors, and adjustments of them are to be done by licensed professionals per an agreement between Walbro and the EPA.

D-shaped adjustment tool

This carburetor adjustment tool is used to adjust the needles on many Walbro carburetors. The "D" shape ers to the end of the screw, which a Phillips head or a flathead screwdriver will not fit. Only licensed professionals have access to this type of screwdriver, which allows for fine tuning of the carburetor while it is running. When a carburetor is adjusted or repaired, the D-shaped screws are loosely tightened while the engine is not running. To complete the adjustment, the engine is started and the screws are adjusted based on the sound the engine produces. Walbro carburetors are installed in two-cylinder engines, but if the mixture of gas and oil produced by the carburetor is too rich, the spark plug will intermittently misfire, making a sound like a four-cylinder engine. The D-shaped adjustment tool tightens the screws, or needles, until the engine sound is smooth and consistent.

500-20 Limiter cap removal tool

This tool is used to remove the plastic limiter cap on some models of Walbro carburetors. Limiter caps are part of the tamper-proof system set in place by Walbro to abide by EPA regulations. Limiter caps cover the screws that adjust the oil and gas mixture. These caps are made of plastic, and the removal tool is similar to a metal hook, which pulls the cap off, leaving the screws open to adjustment.

500-508 Limiter cap removal tool

Like the 500-20 limiter cap removal tool, the 500-508 is used to expose the screws for adjustment. The difference between the two is the size of the cap and the amount of space available to insert the hook for removal.