The T-H Marine Supplies Z-Lock 4" Setback Manual Single Adjust Jack Plate JPZ-4-DP is a heavy-duty HI-JACKER™ series outboard jack plate engineered for V6 and V8 outboard motors up to 300 HP.
Featuring a 4-inch setback, 5 inches of vertical adjustment, aircraft-grade aluminum construction, and patented Z-Lock™ side plate locking design, this manual jack plate eliminates side slippage under high torque loads.
Ideal for bass boats, bay boats, flats boats, and performance fishing rigs seeking improved hole shot, top-end speed, shallow water capability, and prop efficiency.
4" Seatback Jack Plate – Maximum Strength, Zero Slippage
The Z-Lock™ upgrade continues the excellence of the HI-JACKER™ jack plate series by solving a common issue with traditional manual jack plates: lateral side movement.
Matching slotted extrusions mechanically lock the side plates in position, dramatically increasing rigidity and stability under high horsepower loads.
The result is tighter steering response, better engine alignment, and increased confidence at speed.
T-H Marine Z-Lock Performance Benefits
• 4" setback improves leverage and prop efficiency
• 5" vertical adjustment for dialing in optimal engine height
• Enhances hole shot and mid-range acceleration
• Improves shallow water performance
• Helps increase top-end speed when properly tuned
• Reduces chine walk caused by flex and side shift
Z-Lock™ Strength Advantage
• Z-Lock™ design eliminates side slippage
• Matching slotted extrusions lock side plates securely
• Full 1/2" thick aircraft-grade aluminum construction
• Engineered to handle high torque loads from modern V6 & V8 outboards
• Designed for long-term structural durability
Compatibility
• Supports all V6 and V8 outboards up to 300 horsepower
• Compatible with most standard BIA bolt patterns
• Ideal for bass boats, bay boats, flats boats, and performance hulls
• Works with hydraulic or mechanical steering systems
Model JPZ-4-DP Specifications
• Manufacturer: T-H Marine
• Series: HI-JACKER™ Z-Lock™
• Model: JPZ-4-DP
• Setback: 4 inches
• Vertical Adjustment: 5 inches
• Adjustment Type: Manual (single adjust)
• Material: Aircraft-grade aluminum
• Plate Thickness: Full 1/2" material
• Horsepower Rating: Up to 300 HP
• Available Setbacks in Series: 4", 6", 8", 10", 12"
Adjustment System
• Easy top-of-jack adjustment design
• Allows quick height changes without removing the engine
• Fine-tune prop-to-pad measurement for peak performance
Finish & Corrosion Resistance
• Marine-grade aluminum construction
• Designed for freshwater and saltwater applications
• Corrosion-resistant finish for long service life
What’s Included in the Box
• T-H Marine Z-Lock 4" Manual Jack Plate (JPZ-4-DP)
• Installation hardware (where applicable per manufacturer packaging)
• Manufacturer installation instructions
Warranty Information
• Backed by T-H Marine manufacturer limited warranty
• Warranty coverage subject to manufacturer terms and conditions
Why Choose the Z-Lock Over Standard Manual Jack Plates?
Unlike conventional manual jack plates that rely solely on clamping pressure, the Z-Lock™ mechanical locking design prevents side shift under torque load. That means stronger engine support, improved safety at high speeds, and more consistent performance tuning.
For anglers running up to 300 HP who demand reliability and structural integrity, the JPZ-4-DP offers professional-grade performance without the cost and complexity of hydraulic systems.
If you're upgrading your boat for better holeshot, improved shallow water access, and optimized prop performance, the T-H Marine Z-Lock 4" Manual Jack Plate delivers unmatched strength and adjustability in its class. Built for serious anglers and performance boaters who refuse compromise.
WARNING: This product can expose you to chemicals which are known to the State of California to cause cancer, birth defects or other reproductive harm. For more information go to P65Warnings.ca.gov.
