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Performance Bulletin


Engine: Yamaha XF450USA4 / LXF450USA4
Boat: Grady White Express 340
Configuration: Twin
Test Date: 22-Oct-2025
Grady White® - Grady White Express 340

Performance Bulletin

69 - Grady White Express 340

Grady White Express 340

Length 33' 6"
Beam 11' 7"
Dry Weight (Boat Mfr. Pub) 12,360 lbs
Maximum HP 1,050 hp
Fuel Capacity 340 gal
Weight as Tested 17,494 lbs

XF450USA4 / LXF450USA4

Horsepower 450 hp
Induction DI/VCT/DOHC
Displacement 5.6L
Weight (Estimated) 988 - 988 lbs
Gear Ratio 1.79:1

Engine Mounting Height

Mounting Hole Position #2

Propeller(s)

Series XTO Offshore
Diameter x Pitch 16-5/8 x 19
Yamaha Part # 6GR-45974-20-00 / 6GS-45974-20-00
Propeller Material Stainless Steel

Test Conditions

Number of People 3
Air / Water Temperature (Fahrenheit) 65° F / 65° F
Elevation (in feet above sea level) 0'
Wind Velocity 10-15 MPH

Comments

Test weight includes 170 gallons of fuel, 4 batteries, Seakeeper, refrigerator, safety and test equipment.

YPB#: PB_GRW_EXPRESS 340_TW_XF450USA4_10-22-25_ODC

Grady White® - Grady White Express 340

Performance Bulletin


Engine: Yamaha XF450USA4 / LXF450USA4
Boat: Grady White Express 340
Configuration: Twin
Test Date: 22-Oct-2025
XF450USA4 / LXF450USA4

Performance Data

RPM
MPH
GPH
MPG
1000 6.0 3.6 1.67
1500 8.4 5.8 1.45
2000 9.8 9.6 1.03
2500 10.8 14.6 0.74
3000 15.3 20.5 0.75
3500 23.6 24.8 0.95
4000 32.1 31.6 1.01
4500 37.9 41.9 0.91
5000 43.1 53.4 0.81
5500 48.1 67.0 0.72
5950 52.5 78.3 0.67

0-30 MPH: 10.00 seconds

Notice To Consumer The information and data contained in this Performance Bulletin is approximate and subject to many different factors and variables. It is provided as a guideline only and should not be relied upon as representative of actual performance. Your boat’s performance may be different than the information contained in this Performance Bulletin due to various factors, including your boat’s actual weight, wind and water conditions, temperature, humidity, elevation, bottom paint, boat options affecting wind/water drag and/or boat weight, and operator ability. Please confirm the specifications and performance data on your specific boat/engine combination with your dealer prior to purchase. Please also keep in mind that the data contained in this Performance Bulletin may or may not have been performed using Yamaha PowerMatched components. Yamaha reserves the right to change the specifications and performance data of this Performance Bulletin or engine without notice. This document contains many of Yamaha’s valuable trademarks. It may also contain trademarks belonging to other companies. Any references to other companies or their products are for identification purposes only, and are not intended to be an endorsement.