The increasing popularity of V6 four-stroke engines is not surprising considering the many benefits they deliver. Owners can pull into a fuel dock, fill and leave. There is no need to purchase oil with your gas since the oil is changed periodically, just like an automobile is. Owners also appreciate the fuel efficiency, providing incredible savings over the course of a boating season, plus there’s virtually no exhaust smoke during operation. Another significant benefit is the low noise levels. No longer is it necessary to talk loud or even yell to have a conversation at top speed. And speaking of speed, these V6 engines are also full of zest, capable of powering a wide variety of vessels with impressive results.

For 2005, Yamaha introduces a more powerful V6 four-stroke - the F250 - designed to power larger boats that require additional fuel economy for longer runs. Featuring an abundance of innovative technology, the 250 uses a 60-degree 3.3-liter 24-valve DOHC engine block with lightweight forged pistons plus specially heat-treated crankshaft and connecting rods for additional durability and strength. A single-belt drive system uses fewer moving parts for long-term durability, while automatic belt tensioners keep the proper belt tension, eliminating the need to adjust belt tension.

The F250 has a wide-range power trim and tilt that goes from -3 degrees for quick hole shots to +16 degrees to improve top-end. The engine itself features a double-overhead cam design for greater valve timing control and four valves per cylinder to provide clean, powerful combustion. A blow-by gas re-ignition system removes unburned fuel from the exhaust gases and routes it back to the fuel delivery system to be more-efficiently burned.

One of the main differences between the Yamaha F225 (the first V6 four-stroke outboard introduced on the market in the early 2000s) and the new F250 is the addition of Variable Camshaft Timing, dubbed VCT. This feature is designed to increase low and midrange torque, which is most useful for larger offshore fishing boats that are inherently more difficult to get onto plane. The brain of the engine, or Engine Control Module (ECM), directs an oil control valve to vary the supply of oil pressure inside the variable camshaft actuator to advance and retard camshaft timing based on engine rpms. For example, when fully advanced 40 degrees, the camshaft opens and closes the intake valves much sooner than normal, increasing intake and exhaust efficiency by placing the combustion chamber in valve overlap position. The cylinders also build a higher combustion chamber pressure to provide greater volumetric efficiency and a claimed 16 percent gain in torque in the 2,000 to 3,500 rpm range.

Yamaha's V6 four-stroke outboards were initially designed to be more compact, lighter and less complex than other four-stroke models. David Grigsby, Yamaha's product manager is quick to point out that, “the F250 produces all its horsepower without having to add expensive and potentially unreliable technologies like superchargers or turbo chargers”.

For instance, long intake manifolds with a large air intake silencer reduces intake noise and generates more power. Large-diameter intake valves deliver the air-fuel mixture to the combustion chamber more efficiently while the patented In-Bank Exhaust System water-cools the gases and vents them down, out through the propeller hub with reduced exhaust pressure offering increased horsepower. An over-heat prevention cooling system, featuring a 60-degree Celsius thermostat, maintains proper engine temperature for more fuel-efficient operation and additional durability. (Page Top)

Controlling all of this technology is the aforementioned ECM, which receives input from eight sensors placed around the engine. The ECM uses this data to calculate the precise amount of fuel/air mixture the multi-port fuel injection system should send to each combustion chamber depending on load, speed and weather conditions. An Idle Speed Controller provides stable idle and smooth slow trolling. The ECM also warns the operator of any impending problems such as overheat warning, over-rev prevention, low-oil pressure warning, neutral throttle limiter, start-in-gear prevention and keeps the engine running if any sensors fail. Upon service, Yamaha technicians are able to download diagnostic information and engine operating history from the ECM to a laptop computer.

Another strength of the F250 is its level of corrosion resistance. Stainless steel components battle internal corrosion while all aluminum components that contact the water are made from Yamaha's tough YDC 30 aluminum alloy. Zinc anodes in the powerhead, mid-section and lower unit sacrifice themselves to protect other metal components from corrosion.

A front-mounted freshwater flushing device can be used by hooking up a standard garden hose. The F250 does not need to be running to flush the engine. Its super-tight cowling and water-draining air intake ducts route unwanted water away from the engine and drain it out the bottom cowling, while a large water-separator keeps any water in the fuel from entering into the vapor separator.

The F250 is covered with a three-year factory limited warranty.

So how does this combination perform on the water? With five people onboard, and the stainless steel steering wheel in one hand and the twin throttles in the other, the F250s powered the Pursuit up to cruise speed with little effort. Out on the open Atlantic, the smooth and quiet four strokes blended in with the sound of open water as we cruised at 30 mph, turning just over 4,200 rpm. At wide open throttle, we topped 47.2 mph, which was a lower top speed than I had expected, especially if you anticipate travelling 75 miles offshore.

The bow shear is not only beautiful it’s practical. We cut through rough water with ease, throwing spray wide to each side with no hint of blowback. The benefits of this characteristic can only be appreciated if you have endured a wet ride on a long journey.

Fuel is always a concern when cruising offshore. The 3480 has four separate tanks with a total fuel capacity of 375 gallons. One 75-gallon tank is installed to starboard and one to port. A 145-gallon tank is mounted aft of the centerline with a 73-gallon tank just ahead. Based on the amount of fuel that our twin F250s were burning during the test, full tanks will deliver a range of over 500 miles.

The versatility of the F250 Yamahas on this new Pursuit was clearly demonstrated. The linear power and smooth acceleration of four-stroke power greatly improve thrust. Low speed cruising is better too with acceleration to higher speeds just a push on the throttle away. (Page Top)

Our Our Test Boat: Pursuit 3480 CC
Our testing platform was Pursuit Boats’ all-new 3480 Center Console, a hefty workhorse designed to break into the top ranks of the popular offshore center console market.

Taking the helm of a big center console is very empowering. With 18 toggle switches, 17 circuit breakers, a Furuno NAVnet, autopilot, radios, mechanical tab indicators and a myriad of gauges, you have one very impressive helm. The helm seating system offers comfort while sitting or standing thanks to a flip-lip seat bottom that converts to a bolster.

The console comes equipped with the available marine head and easy access to the batteries, oil fills, stereo/CD player and key rigging. Under the seat is a standard 55-gallon live well with tackle storage built into the top and sides. Rig the boat with Pursuit’s custom optional T-top and you’re offered one more storage box overhead that’s perfect for a second radio or additional electronics. The T-top features a total of nine premium rod holders and is constructed of aluminum with strategically placed handholds and plates for rigging.

The diamond pattern, non-skid deck space surrounding the center console is extremely generous. With 13 feet forward to the bow and eight feet, six inches behind the console to the transom plus almost eight feet between the gunnels, this has to be one of the most spacious center console boats in it’s class. Large deck channels positioned outboard and under the gunwales drain water quickly.

The 3480’s profile reveals a classic shear with bow rails recessed on the interior of the gunwale cap. All hardware including premium stainless pop-up style cleats and navigation lights are flush-mounted. The gunwale is fully bolstered from bow to stern with heavy-duty vinyl. To starboard are under-gunwale rod racks for gaffs and other essential gear and four large, insulated, gasketed boxes can hold your catch or ice.

On the construction side, Pursuit has incorporated a notched transom combined with a 24.5-degree deadrise for optimum speed and a solid ride. The stringer system, hull, deck and cap joints are fastened with stainless bolts, premium bonding materials plus a three-piece construction method that’s designed to offer a high performing fishing machine ready for any big water challenge. (Page Top)

Specifications:
YAMAHA F250

Engine: 60-degree V6
Displacement: 3,352 cc/204.6 ci
Bore & Stroke: 3.7”x3.17”/94x80.5mm
RPM Range: 5,000-6,000
Induction System: DOHC EFI
Alternator Output: 45 Amps
Fuel Delivery: EFI
Starting: Electric
Exhaust: Through Prop
Gear Ratio: 15:30
Shaft Length: 25”/30”
Prop Configuration: Three-blade
stainless
Weight: 592 lbs./269 kg

PURSUIT 3480 CENTER CONSOLE

LOA: 34’ 5”/10.51 m
Beam: 9’6”/2.92 m
Deadrise: 24.5 degrees
Draft: (engines up) 1’10”/0.02 m
(engines down) 2’6”/0.06 m
Weight: 9,000
(approx. dry weight w/o engines)
Maximum Horsepower: 600 hp
Approx. Base Price: $161, 400 (US)

Speeds:
RPM Miles Per Hour
On Speedometer On GPS
4,000 27 mph 26.7 mph
4,500 34 mph 33.3 mph
5,000 38 mph 37.9 mph
5,500 43 mph 42.3 mph
6,000 48 mph 47.2 mph

For more information contact:
Yamaha Canada, 416-498-1911 or www.yamaha-motor.ca

Price supplied by:
Pursuit Boats, Fort Pierce, FL. 772-465-6006 or www.pursuitboats.com (Page Top)