Mercury Verado V12 and Other Large Outboard Engine Surveys and Inspections

 

Mercury Verado V12 and Other Large Outboard Engine Surveys 

By Capt. John Banister, AMS

Large outboard engines (high horsepower, eight cylinder to 12 cylinder outboard engines) require a lot more work and advanced training compared to smaller outboard engines. Large outboard engines such as the Mercury Verado V12 outboard engine (pictured here to the right) require very specific training to properly service, diagnose, repair, and survey. Large eight cylinder to 12 cylinder outboard engines typically take longer to inspect and test than a comparable four or six cylinder outboard engine. Large outboard engines typically are rated at higher horsepower, produce more torque, endure more load, and propel larger vessels through the water. These larger outboard engines typically have more electronics integrated into them and are mostly digitally controlled. Larger eight cylinder to 12 cylinder outboard engines cost more to purchase and to maintain compared to smaller outboard engines, therefore large powerhead engine surveys require a more in depth, comprehensive mechanical inspection. This is crucial for evaluating the health of the outboard engine (or multiple engines). These specialized outboard engine surveys are important before a prospective buyer or owner purchases the vessel, renews the insurance on the vessel, considers warranty repairs or manages the maintenance of the outboard engines.

To illustrate the uniqueness of the Mercury Verado V12, the Mercury V12 outboard engine has an automatic two-speed transmission located in the mid-section of the engine that is integrated into the drive system of the outboard engine. This two-speed automatic transmission was developed in partnership with ZF Friedrichshafen AG (ZF Marine), based in Friedrichshafen, Germany. The two-speed transmission is designed to maximize torque during heavy loads and to improve fuel economy at high speeds. This transmission is unique in its design and operation and is tested and loaded during an outboard engine survey of the Mercury V12 outboard engine. 

In many cases, larger outboard engines are the most expensive components of the vessel. Typically larger outboard engines cost anywhere from $45,000.00 to over $77,000.00 per engine.

Some fun facts about the Mercury Verado V12 outboard engine; The Mercury V12 outboard engine is a 12 cylinder, 7.6 liter, naturally aspirated outboard engine. The heads are angled at 64 degrees and the powerhead has 48 valves (four valves per cylinder). The standard Mercury Verado V12 is rated at 600 horsepower. Mercury also offers a commercial-grade V12 SeaPro version rated at 500 horsepower. The dry weight of the Mercury V12 outboard engine is 1,260 pounds. The outboard engine is completely raw water cooled and has an integrated power steering system with a 150 amp alternator. The engine steers at the lower unit on a large sealed kingpin. 

The inspection process and testing of large outboard engines during the marine engine survey require some (or all) of the following (depending on the year, make, and model of the V8 - V12 outboard engines):

• Sea trial (running the engines at wide open throttle, backing the engines down, and hard over turns to inspect the steering assembly and joystick controls)

• Digital integration checks at the binnacle, digital gauges, and joystick (if equipped)

• Compression testing

• Borescope viewing of the cylinders, pistons, and lower unit exhaust passages

• Inductive testing of the ignition systems

• Infrared thermal imaging of the powerheads and transmissions to ensure proper temperature anomalies throughout the engines while running

• Computerized marine engine diagnostics (includes dynamic testing, static testing, and component activation of the engine's components. To learn more about marine engine diagnostics click here)

• Inspection of the steering assembly (digital integrated or bolt on 12 volt / hydraulic steering systems)

• Inspection of the engine's electrical actuators or hydraulic systems

• Oil analysis to search for unusual wear metals and foreign substances in the engines

• Testing of the fuel to search for phase separation, contamination, excess water or Ethanol in the fuel

• Sampling the two-speed transmission fluid (Mercury V12 outboard engines only)

• Proper rectified and regulated voltage to insure the engines are charging the batteries when running

• Running a search through databases to search for warranty history and fix campaigns (service bulletin related repairs that are needed on the engines)

• An overall visual inspection of the engine to look for things such as galvanic corrosion, back probing, worn timing belts, proper belt tension, proper wiring connections, improper previous repairs, etc.

Below are some of the most common larger outboard engines I am qualified to survey: 

• Mercury Verado V12, 7.6 liter 600 HP outboard engines 
  

• Mercury Verado V10, 5.7 liter outboard engines

• Mercury Verado V8 4.6 liter outboard engines

• Yamaha XTO Offshore V8 5.6 liter outboard engines

• Yamaha F350 V8 5.3 liter outboard engines

• Honda BF350 V8 5.0 liter outboard engines 

If requested or recommended, I can conduct more advanced inspections and testing during the marine engine survey or analysis. I can also provide diagnosis or determine the mechanical failures. These advanced inspections and testing I can perform are detailed here.

I am certified as a technician in several outboard engines, on specialized marine technologies, and have earned two SAMS® designations (Yachts and Small Craft and Engine-Gas). My combined training, education, and technical certifications can be found here. 

Please contact me if you would like to arrange a marine engine survey or engine analysis at (561) 255-4139 or via my contact page here. I would be more than happy to discuss it with you and can combine it with a pre-purchase and valuation survey for a prospective buyer.