I like an outboard with spunk, so it was fun to get re-acquainted with the Yamaha V MAX SHO 115, which I found rigged on a new Ranger RP190 at Yamaha’s recent press event held on the harbor in Baltimore, Maryland. This aluminum-hull bay boat proved a perfect match for this quick outboard.
Introduced in late 2015, the SHO 115 is a “hopped-up” version of the 1.8-liter F115. Tuned to maximize top-end performance, the SHO 115 has revised camshafts, a re-mapped ECU, and electronically controlled throttle. The WOT rpm range is bumped up to 5300-6300 from the 5000-6000-rpm range of the standard F115B. And to make you feel like you’re going faster, the SHO 115 is dressed in the same red, black and gold graphics used on the big V6 SHO-model Yamaha outboards.
According to the Yamaha SHO 115 spec sheet, power peaks at 5500 rpm. But on the right boat with the right prop, that extra 300 rpm at the top and the extra top-end power delivered by the camshafts should produce an increase in top speed; or you could go down a little in prop pitch for better acceleration without losing top speed. Yamaha claims the SHO 115 is good for an extra 2.7 mph (50.75 mph) over its F115B motor on a Skeeter TZX 170, a 1,300-pound, 17-foot fiberglass bass boat. The Ranger we ran is 18’ 8” long and does not have the benefit of the pad running surface found on the bass boat, but it also only weighs 1,150 pounds. The SHO 115 pushed it to 45.1 mph, and we planed off in just over four seconds, all while running a 16-pitch Yamaha Talon three-blade aluminum prop equipped with the Yamaha Shift Dampener System (SDS™) hub.
Yamaha would not provide a torque curve graph for the SHO 115. I’d like to compare that to the curve for the F115B motor. I suspect the power gain is mostly on the top end, and so will most-benefit lighter boats that make some hull lift and can get up and go with some trim. Mercury has applied the same formula–raise the peak rpm and re-map the fuel delivery – on its new 115 Pro XS. The Suzuki DF115 SS and the Evinrude 115 H.O. are also tuned to deliver a little more power and are styled to look like big performance motors. All four of these outboards are likely tuned to make about 126 HP; the “industry standard” allows a plus-or-minus deviation of 10 percent on the advertised power, and you can be sure each of these outboards takes full advantage of that allowance. So given that peak power is going to be about equal, engine weight and displacement become key factors in real-world performance. As the boat gets smaller the weight of the motor becomes more significant in its effect on hole-shot acceleration. Displacement can give the motor more “grunt” in the mid-range. Here’s a quick comparison of the four high-performance 115-model outboards.
Each of these motors will be priced $200 to $300 higher than the standard 115 model, depending on the discounting offered to a dealer or the boat builder.
For more information about the Vmax SHO 115 visit Yamaha, and for more information about all these outboard engines visit Mercury, Suzuki, and Evinrude.