Cylinder Base Nut Wrench – 3/4" | Lycoming Wide Deck Engine Tool

Designed for cylinder removal, installation, and engine overhaul work, this professional-grade 3/4" Cylinder Base Nut Wrench provides the reach and clearance needed to access difficult cylinder base nuts on Lycoming Wide Deck enginesand other compatible engine applications.

The 15-inch span reaches around the cylinder barrel, while the extra-thin 0.14" wall provides access in tight areas where conventional sockets and wrenches may not fit. The 12-point end works with both hex and 12-point nuts, and the 1/2" square drive allows use with a compatible torque wrench or breaker bar.

Forged from 4130 steel, tempered for maximum strength, and finished with industrial chrome plating, this specialty wrench is built for repeated engine maintenance, cylinder changes, and overhaul work.

Product Features

• Hex Size: 3/4"
• Drive Size: 1/2" square drive
• Span: 15" (381 mm)
• Wall Thickness: 0.14" (3.5 mm)
• 12-point end fits both hex and 12-point nuts
• Long-reach design fits around most engine cylinders
• Thin-wall construction provides access to tight cylinder base nut locations
• Forged from high-strength 4130 steel
• Tempered for maximum strength and durability
• Industrial chrome plating improves surface hardness and corrosion resistance
• Quality tested to meet or exceed engine manufacturer torque specifications

Engine Compatibility

This 3/4" Cylinder Base Nut Wrench is most commonly used with:

Lycoming

• Wide Deck engine applications
• IO-390-D Series
• IO-390-D2 Series
• Other Lycoming engines utilizing compatible 3/4" cylinder base nuts

Continental

• Select older Continental A-Series engine applications
• Other Continental engines utilizing compatible 3/4" cylinder base nuts

Fitment Note: Verify the cylinder base nut size on your specific engine before ordering, as hardware can vary by engine model and configuration.

Ideal for Engine Maintenance

Perfect for:

• Cylinder removal and installation
• Cylinder replacement
• Top overhauls
• Complete engine overhauls
• Cylinder base nut removal
• Cylinder base nut torquing
• Engine teardown and assembly

Important Torque Note

When this wrench is used as an extension with a torque wrench, the effective lever length can affect the actual torque applied to the fastener. Follow the applicable engine manufacturer's torque procedure and use the appropriate torque correction when required.

Airboat Solutions

A professional specialty tool for maintaining and rebuilding Lycoming and Continental-powered airboat engines, particularly Lycoming Wide Deck applications where access to cylinder base hardware requires a purpose-built wrench.

Size: 3/4"
Drive: 1/2" Square
Span: 15" (381 mm)
Wall: 0.14" (3.5 mm)
Material: Forged 4130 Steel
Finish: Industrial Chrome Plated