Mitsubishi 4G63, 4G64 Gasoline Engine Service Manual

Technical Scope of the Mitsubishi 4G63 and 4G64 Service Manual

• This 101-page technical reference provides service data for the Mitsubishi 4G63 and 4G64 gasoline and LP-gas engines used in forklift applications.
• Official OEM publication P/N 99729-74120, issued as the primary reference for the AA0001–YY9999 engine serial number range.
• Contains 26 detailed exploded-view assembly diagrams covering the cylinder head, timing belt, lubrication system, fuel system, and starter motor.
• Includes 39 technical specification tables featuring tolerances, wear limits, tightening torque values, and electrical reference settings.
• Re-download the file any time, no expiration.
• Suitable for printing individual sections for shop-floor use.
• Features an OCR text layer for quick navigation through service specifications and engine adjustment chapters.
• Cross-reference lookup works via the built-in search.
• An official Mitsubishi OEM publication, this document covers the mechanical service, adjustment, and component assembly for the 4G63 and 4G64 engine family used in material-handling equipment.

Engine Documentation Overview

This Mitsubishi 4G63 and 4G64 service manual covers the detailed inspection and assembly procedures required for maintenance. The documentation begins with general information, engine model identification, and performance curves for both gasoline and LP-gas configurations. Subsequent chapters provide technical guidance on the timing belt assembly, including the adjustment of tensioners and sprockets, followed by in-depth sections on the lubrication and cooling systems. Fuel system components, such as the down-draft carburetor and air governor, are detailed with removal and reassembly points to ensure correct settings after maintenance.

Additional chapters focus on the internal engine components, documenting the cylinder head, valves, rocker arms, and camshaft configurations. The text provides specific assembly information for the crankshaft, pistons, and connecting rods, including the plastic gauge method for oil clearance verification. Detailed alternator and starter motor service sections conclude the document, offering electrical test values, connector data, and troubleshooting paths for common operational symptoms.

Engine Specifications and Tightening Data

Technical data is provided for critical engine measurements, including bore and stroke, compression ratios, and valve timing. Valve seat and guide replacement procedures are documented with precise oversized dimensions for machine work. The manual provides extensive torque charts, listing values in N.m, kgf.m, and lbf.ft for all major bolts and nuts. Cylinder head bolt torque is specified at 20 N.m plus a 1/4 turn, while connecting rod bearing bolts require 10 N.m plus a 1/4 turn. Ignition timing for the 4G63 is documented at 4° BTDC for gasoline versions. Coolant system capacity is listed at 3.1 liters for this engine range. Intake valve clearance is not required due to the automatic lash adjuster system documented in the maintenance section.

Document Reference: 99729-74120