Yamaha has released two new versions of the 115 and the 175 4-strokes engines. The 115 is the new F115B and the 175 the new F175A.
Looking at the F115B, it’s interesting to see that Yamaha have not simply upgraded their existing 115, which has naturally undergone a few modifications since it’s initial release in 1999. The truth of the matter is that the F115B is an entirely new engine. Lighter, stronger, more powerful; let’s look at some of the features.
The new F115B is 15kg lighter than the original. It remains a four-cylinder engine but now has 1832cc against the F115A’s 1741cc. In line with latest technological advances there’s increased compression and an increased full throttle operating range. Dual overhead camshafts are also featured, as are four valves per cylinder and multi point Electronic Fuel Injection. Along with a knock sensor (unusual in an engine of such modest horse power), the new engine systems are designed to provide smoother operation and greater efficiency throughout the entire rev range.
There’s also a new cowling design with an air intake drain within the induction system to prevent water from contaminating intake air. The new F115B also boasts best in-class charging power increasing from 24A (F115A) to 35 amps at wide open throttle. Yet even at 1,000rpm there’s sufficient output to keep the engine battery charged.
One feature sure to be welcomed is a water separating fuel filter. Should water be present in fuel a ‘Water in Fuel ‘ warning will be activated. Another useful addition is a single ram power trim and tilt system with tilt angle adjustment to prevent over tilt damage.
Another breakthrough is the optional Yamaha Command Link that gives provision for the F115B to be linked, via Yamaha’s own digital network system, to a wide range of instruments via a multi function tachometer. There’s also a valuable security system that is available within Command Link.
Time on the water also proved the power and efficiency of the new F115B. I was fortunate enough to take the helm of a Cruise Craft 530 Explorer powered by the new Yamaha. For the record this is not a lightweight hull chosen by Yamaha to be an impressive test bed. No sir. The 530 Explorer’s hull weighs 1094kg and has a maximum engine rating of 140hp. Was it underpowered? Certainly not.
With two aboard the craft fairly jumped onto the plane in around three boat’s lengths at 3000rpm, then settled back to travel at 15.8km/h. 4000rpm proved a very quiet and smooth cruising speed with 38.9km/h recorded. Fuel consumption at those revs was a very creditable 37.2L per hour that saw 2.26km travelled per litre. 5,000rpm saw a speed of 52.5km/h.
I saw the F115B as an impressively quiet and high performing engine with a pleasing degree of throttle response through the entire rev range.
The ‘A’ classification by Yamaha denotes the 175 as a totally new engine, designed to fill a niche in Yamaha’s product range between 150 and 200hp outboards.
The new F175A is based on Yamaha’s award winning and recently released 2.8L F200 platform that sees the F175A sharing the same displacement as the powerful F200.
The F175A is a DOHC EFI 16 valve engine (four per cylinder) weighing only 219kg. It features a wet sump lubrication system same as the F115B and has a class leading 0 Amp high output alternator and multi point Electronic Fuel Injection for ultimate engine response and smoothness of running.
There’s also Yamaha’s patented Shift Dampening System for smoothest gear changes, a tilt limiting switch on the engine trim, plus latest generation slim line styling for ease of fitting dual engines. A variable trolling switch is standard when Command Link gauges are fitted.
Engine oil coolers are standard for optimum engine performance and longevity. It’s pleasing to note that the fuel system is protected by an early warning system to prevent water or other contaminants from entering the fuel system. An audible warning sounds if fuel contamination is detected.
Options for the F175A include 6Y8 LAN/Command Link gauges, a Digital Network System for engine management, and Yamaha’s YCOP immobiliser system that prevents theft.
Test runs for the F175A were undertaken in a Cruisecraft Explorer 625, a solid Deep Vee hull with a weight of 1370kg. With three aboard the craft cruised creditably at 4,000rpm at 42.8km/h. Engine noise was pleasingly quiet with normal speech par for the course.
The power of the F175A was impressive. The craft jumped onto the plane in less than four or five boat lengths and from plane to WOT the 175 provided rapid acceleration when the throttle lever was pushed forward.
Both new engines run on regular unleaded fuel and come with 4 years recreational use warranty and have a 3 star Ultra Low Emission rating.Reads: 1805