Spring is a great time for newbie and veteran performance boaters alike to get familiar with their craft. For starters, you should review your owners manuals — really, you should — and review the key components of your new boat.
Performance boats vary widely in propulsion and size. Outboards come in 20, 25 and 30-inch drive shaft lengths to accommodate a variety of applications. Mercury (and other brand) outboards are fitted with a standard gearcase for most applications. Hulls that can take advantage of the high power-to-weight ratio of a 300XS may benefit from its wide range of gearcase options. Similarly, Mercury Racing offers a variety of sterndrives for differing power capacities and hull types.
Mechanical control: High performance outboards are usually rigged with with dual steering cables, a shift cable, throttle cable and fuel line. With performance sterndrives, throttle and shift are accomplished with cables, but steering is hydraulic. These include 600 SCi and 700 SCi Mercury Racing packages.
Digital control: On Digital Throttle & Shift compatible outboards, such as the 400R and sterndrives including the 520, 540, 565, 860, 1100, 1350 and 1550 mechanical throttle and shift cables are gone — replaced with a single electronic cable. Steering is either electric (Verado) or hydraulic (MerCruiser).
OpiMax 300XS models feature a heavy-duty swivel/clamp bracket and trim cylinder to endure the rigors of extended use in rough seas. The trim cylinder is actuated via a remotely mounted pump. A majority of today’s outboards feature trim systems mounted within the swivel clamp bracket assembly. Verado outboards come equipped with integral power trim and steering. OptiMax outboards come standard with mechanical steering.
Two steering system types are available: Full Feedback and No Feedback. With Full Feedback, steering loads from an outboard or sterndrive are continually transmitted to the steering wheel. This is the preferred system used by tunnel boat drivers for “feel” of their craft while driving at the limit. One disadvantage: steering forces increase as engine or drive height or trim is increased. The steering wheel must be secured at all times to maintain control.
With No Feedback, steering torque is only felt when the steering wheel is turned. This system is more forgiving and best for a recreational performance boater. If you relax your grip on the steering wheel, the boat will continue on your selected course. It is important to have minimal free play or steering “slop” in any performance boat steering system.
Mercury Racing sterndrive packages are equipped with power steering. The system requires actuation of external hydraulic steering cylinders. Our Integrated Transom System (ITS) provides external power steering for Bravo One XR, Bravo One XR Sport Master and Bravo Three XR drive engine packages. Power trim and steering cylinders are integrated in the M-series transom plate that comes standard with all engine packages featuring NXT1, NXT6 and M8 sterndrives.
Performance boats with two or more outboards or sterndrives are rigged with both external power steering cylinders and tie bars. These components work together to minimize steering backlash and enhance drive stability.
The units tied together (outboards or sterndrives) should be adjusted parallel to each other, at rest, where play in the steering can be adjusted to zero. Always be sure to have a qualified professional check to ensure your outboards or sterndrives and all related components are mounted securely.
Most larger outboard and sterndrive performance boats feature hydraulicly actuated K-Plane trim tabs. Tabs are used to assist getting the boat on plane and for hull attitude adjustments in varying seas. They can be used independently or in conjunction with outboard or sterndrive trim adjustments.
In Hi-Performance Boat Operation – Part 3, I’ll interview Brad Schoenwald from the Tres Martin Performance Boat School. Brad and I will discuss basic performance boat operation.