Tuning A Propane-Powered Forklift

Most of the industry may be turning to electric forklifts for their zero emission benefits. However, there are some warehouses that are still using gasoline-powered forklifts, more specifically propane (a.k.a. LPG forklifts.

It is essential for the CO2 emissions of a propane-powered forklift be limited if for no other reason than the health of the people who work inside the warehouse including the forklift operators.

Limiting the CO2 emissions of a propane-powered forklift can be achieved by adjusting the carburetor.

There are four procedures that need to be performed when tuning the carburetor of a propane-powered forklift.

The first of the procedures is to perform a pre-adjustment inspection following these checklist issues.

  •  Ensure that the air filter of the carburetor is clean and properly installed.
  • Inspect the timing and adjust to manufacturer’s specifications.
  • Ensure that the idle RPM is set at the manufacturer’s specific speed.
  • Make sure that the engine is at operating temperature when you perform the next three procedures.

The next thing to focus on a propane-powered forklift is the idle adjustment. The procedure for achieving a proper tune of this part of the process includes:

  •  Checking the CO2 in the exhaust pipe to be certain that it is between 0.4 percent and 0.7 percent.
  • If there is too little CO2 in the exhaust pipe, then turn the idle mixture screw towards the “richer” direction. This will raise the CO2.
  • If the CO2 in the exhaust pipe is below 0.4 percent, then turn the idle screw out toward the “leaner “ position. This will reduce the CO2.

A propane-powered forklift’s carburetor.
(Courtesy: Blake Industries)

Next focus on the the power adjustment of a carburetor on a propane-powered forklift. The checklist concerning this aspect of the tuning process includes:

  • Setting the parking brake and blocking the drive wheels.
  • Bringing the engine to full governed RPM.
  • Tilting the mast back until the hydraulic pump reaches relief bypass.
  • Ensuring proper operation of the hydraulic bypass.

Once that is done, it is now time to make power adjustments on the carburetor of a propane-powered forklift. This procedure includes:

  • Checking the CO2 levels in the exhaust pipe when the engine is running at the hydraulic relief bypass. The proper level should be between 0.4 percent and 0.7 percent.
  • Turning the power mixture valve of the carburetor toward the “rich” side to raise the CO2 when the level is below 0.4 percent.
  • Turning the power valve toward the lean direction when the CO2 level is above 0.7 percent.

If the CO2 levels in the exhaust pipe are between 0.4 and 0.7 percent, then the engine will operate well.

It is advised that you refer to the manufacturer’s specifications for each particular engine and carburetor combination of your propane-powered forklift fleet. In other words, always refer and rely on the OEM’s specifications concerning CO2.

(Source: Blake Industries)

*For expert mechanical advice or service ALWAYS contact your local forklift dealership service department.

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