The 115 hp outboard is something of an anomaly. Starting with the 9.9 hp engines, horsepower ratings tend to go up in 10 to 15 hp increments. The big V-6s invariably rise in 25 hp jumps, but the 115 has the distinction of being the odd man out. The jump from a 90 to a 115, proportionally, is a huge leap, but the gap between the 115 and a 150 is positively chasm-like. And when you consider that a majority of boats in the U.S. are less than 20 feet long, a lot of boat owners have to make a tough choice on many models.
Boaters are always looking to save money, and the lure of saving thousands of dollars leads many to opt for the 115 over the 150. And many boats with a max horsepower of 150 do just fine with a 115, such as the Stingray 194LX, which can hit a top speed of 47 mph with a Yamaha F115. But for others, the 115 is a ’tweener.
The Big SHO
When Yamaha unveiled its new V MAX SHO 250, it set a new standard for four-stroke outboard power by coming in at or below the weight of two-strokes and by outperforming them. Largely designed for the freshwater bass-boat market, the 250 started showing up on other boats, like pontoons, much to Yamaha’s surprise — but who doesn’t want better performance? This year, starting in April, boaters looking for a new 115 will find the performance gap between it and the 150 bridged with the V MAX SHO 115 (aka VF115). Pushing the allowable horsepower rating boundary by around 10 percent, the 115 is more like a 125-plus. And it revs higher than the F115 by 300 rpm when it hits its peak of 6300 rpm. Yep, it’s a hot rod all right and might be just the ticket for boaters who want that little extra kick of power.
Fast, Faster, Fastest
The 1.8L four-cylinder VF115 features an advanced 16-valve, dual overhead cam design that uses a large single 60 mm throttle body and employs Yamaha’s Long-track intake to help it make plenty of power, especially in the mid-range. At 377 pounds, only the Mercury FourStroke 115 is lighter (by 18 pounds), but that engine features a simpler design with two valves per cylinder and only one camshaft. Yamaha reduced the weight over its earlier generation F115 design by using lighter components, such as a composite cowling and lower oil pan. It also only uses one ram for its trim-and-tilt mechanism and features a lightweight mounting bracket. A free-flowing 4-into-1 exhaust system makes sure it can breathe easily.
So what’s the difference between the F115, which was totally redesigned and introduced last year, and the new V MAX SHO 115? Aside from the obvious sporty cowl that takes its graphic design elements from the V MAX SHO 250 you see the top bass pros using, there are a couple of key differences. The major one is the racier cam-shaft design that allows it to reach 300 more rpm and a higher top speed. When Yamaha engineers tested a Skeeter TZX 170 with its 115s, the V MAX SHO 115 was nearly 3 mph faster than the current F115 and almost 4 mph faster than the previous generation F115. The rest of the increased horsepower and top speed comes from different engine mapping in the ECU (the engine’s computer brain). Yamaha’s Shift Dampening System (SDS), which vastly reduces the clunking sound from the force of shifting gears, was introduced in 2011 for the F350 and has slowly worked its way into the four-stroke lineup, and this year it appears on the VF115.
Let It Rip
Our test on the Tennessee River at Yamaha’s Bridgeport, Ala., test facility was conducted on a Sweetwater 2280 SLC triple-tube pontoon, and the first thing we noticed was its quietude. The wind was making more noise than the engine. Because you’ll probably try to start a running engine, accidentally, it would be nice if it had a failsafe override, like some other model Yamahas have, so you won’t be scolded by a screeching starter. Even at wide-open throttle, it only hit 88 decibels, which is super quiet. The second thing we noticed was the snap of acceleration when we jammed the throttle. The Sweetwater was on plane in 3.2 seconds, and the Yamaha pulled hard to 25 mph in 7.5 seconds. It reached an average top speed of 36.1 mph, after running both directions in the stiff current. It’s clear this four-stroke outboard will be a huge hit with owners who have flats boats, compact bay boats, budget bass wagons and mid-sized pontoons. Anglers who troll will love the Variable Trolling Speed (VTS), which allows an angler to dial in the perfect speed. Fuel economy, according to Yamaha’s test results, worked out to 5.57 mpg at 3500 rpm at 16.7 mph.