Express Mach4 Propeller 15.3x13 – 4-Blade Stainless Steel, LH (Counter) Rotation

Express Mach4 15.3" x 13" 4-Blade Stainless Steel Propeller – Left Hand (Counter) Rotation

The Express Mach4 is a race-proven stainless steel propeller engineered for high-performance applications where acceleration, stern lift, and rough-water handling matter most. The 4-blade design delivers faster hole shots, better load-carrying ability, and a smoother, more planted ride compared to 3-blade alternatives — all backed by proprietary TP17™ stainless steel and precision casting technology.

This 15.3" x 13" left-hand (counter) rotation version is designed for dual-engine setups and specific engine configurations that require counter-rotating props. Always verify rotation direction against your engine's requirements before ordering.

Key Features

• TP17™ Proprietary Stainless Steel – A custom alloy formulated for higher strength, superior corrosion resistance, and a mirror-quality finish that holds up in saltwater and freshwater alike.
• 4-Blade Design – Delivers faster acceleration, better stern lift, improved handling in following seas and rough water, and maintains speed more effectively under load compared to 3-blade props.
• Performance-Tuned Geometry – Pitch, rake angles, and exhaust vents are precision-tuned for all-around performance gains across the RPM range.
• MaxSpeed™ Dyno Balance – Each prop is dynamically balanced to eliminate vibration and maximize smooth power delivery at high RPM.
• Left Hand (Counter) Rotation – Engineered for counter-rotating twin-engine setups or specific single-engine applications requiring LH rotation. Confirm your engine's rotation requirement before purchasing.

Compatibility & Hub Kits

Requires a Series 500 or Series 700 hub installation kit (sold separately). Consult the application chart for your specific engine and required kit number. Compatible hub options include the MasterGuard Hub Kit 500, Hub Kit 501, Hub Kit 502, and the MasterGuard 700 Series Hub Kit. For sound-dampening applications, see the MasterTorq 800F SDH Hub Kit.

3-Blade vs. 4-Blade

The 4-blade Mach4 excels in acceleration, load carrying, and rough-water stability. If your priority is maximum top-end speed on a lighter, performance-oriented hull, the Express Mach3 3-Blade Stainless (RH) or Express Mach3 3-Blade Stainless (LH) may be worth comparing.

Parts Desk Insights

Best Use Case: Dual-engine setups requiring counter-rotation on the port side, or single-engine applications specified for left-hand rotation. Also ideal for customers running high-HP engines (90–300+hp) who want improved acceleration, better performance in rough water, or are carrying heavy loads regularly.

• Confirm rotation direction first — LH (counter) rotation is not interchangeable with standard RH props. This is the most common ordering mistake on twin-engine boats.
• Hub kit is mandatory — do not sell without confirming the customer has a compatible Series 500 or 700 kit. See Hub Kit 500, 501, 502, or 700 Series.
• 4-blade upsell story — customers upgrading from a 3-blade OEM prop will notice meaningful gains in hole shot, rough-water handling, and load performance. The 4-blade is the right recommendation for pontoons, tri-toons, and heavily loaded boats.
• Stainless vs. aluminum — customers comparing to the Hustler 4-Blade Aluminum LH should know stainless holds pitch better under load, resists flex, and lasts significantly longer in abrasive or saltwater environments.
• Verify gearcase diameter and HP range against the application chart before confirming fitment.