Rough idle, hard starts, and poor fuel economy on a Mitsubishi 4G33, 4G52, or 4G54-powered forklift usually trace back to overdue ignition parts. A single tune-up kit covers all three of these related engine families and gets you back to a clean idle.
Signs your forklift needs a tune-up
- Rough or uneven idle
- Hard starting, especially when the engine is cold
- Noticeable drop in fuel economy or power
- Engine misfire under load
Compatibility
This kit is built for the Mitsubishi 4G33, 4G52, and 4G54 engine family, commonly found across multiple forklift brands that used Mitsubishi power plants.
What's included
The kit centers on a DENSO W14EXR-U spark plug — an OE-quality plug matched to this engine family's heat range and thread spec, which matters more than people expect: the wrong heat range causes exactly the rough-idle and hard-start symptoms above.
Installation overview
With the engine cool, remove the old plugs one at a time (to avoid mixing up wire routing), gap-check the new plugs against Mitsubishi spec, and torque them to spec — overtightening a spark plug is one of the most common causes of stripped threads in aluminum heads. Reconnect wires in their original positions and start the engine to confirm a smooth idle.
Get the part
We stock this tune-up kit ready to ship. View the Mitsubishi 4G33/4G52/4G54 tune-up kit →