Fork Lift Tune-Up Guide

Low Emissions Forklift Tune-Up

Recommended procedures for a low emissions tune-up for propane (LPG) powered forklifts.


Fork Lift CarburatorPre-adjustment Check List

  • Be sure the air filter is clean and installed.
  • Check the timing and adjust to manufacturer’s specifications.
  • Check to insure the idle RPM is set at factory specified speed.
  • The engine must be at operating temperature.

Idle Adjustment Procedure

  • At idle, CO in the exhaust pipe should be between 0.4% and 0.7%.
  • Turning the idle mixture screw in (richer) will raise the CO.
  • Turning the idle screw out (leaner) will lower the CO.

Power Adjustment Check List

  • Set the parking brake and block the drive wheels.
  • Bring the engine to full governed RPM.
  • Tilt the mast back until the hydraulic pump reaches relief bypass.
  • Check for proper operation of the hydraulic bypass (RPM drop).

Power Adjustment Procedure

  • With the engine operating at the hydraulic relief bypass, CO levels in the exhaust pipe should be between 0.4% to 0.7%.
  • Turning the power mixture valve toward R (rich) raises the CO.
  • Turning the power valve toward L (lean) will lower the CO.
  • These CO levels are general limits where most engines operate well. The best source of these levels is the factory specifications for each particular engine and carburetor combination. Always refer to the OEM’s specifications for CO
    exhaust emissions.

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