[Edogaa]

lets not forget that your 115 inline 6 merc is crank rated, not prop rated. That being said, your 115 in reality is only producing between 90-95 h.p at the prop. If you were to buy a 115 outbpoard AFTER 1986 then you would get a true prop rated engine which would be noticably stronger than your inline even though your inline is a 6 cylinder. you should be wondering how well a 90 does on that 18 foot boat, not a 115 and IMO 30 mph w/ a 90 is not too far off for an older 18 footer. here

[hjordanfishere]

Take Clams advice. He knows best!

[TigerWolf]

That's a good question. There is no RPM gauge on the boat and I tried to hook an automtive gauge without sucess. in reading some earlier post, I found to where this wouldn't work anyways. And I really have nothing to compare it to by ear so I couldn't even guess.

[destine]

Re: How fast should a 115 go? here

[dabbad]

I cleaned the carbs and fuel pump and tried it. It would drag it's butt in the water and that was it. I broke my timing belt just checking it and replaced it. I tried it and it throttled up like it wanted to jump out of the water and then acted like it was starving for fuel before it got up. I adjusted the timing belt notch by notch and found the optimal notch for best preformance. (only had to adjust 4 times.) But still, it took a while and some finness (<-sp?) with the throttle to get it to plane. And I still couldn't find any sweet spot in the throttle like it was flodding out or anything. Once it was up, no more hesitation until you tried to turn with it and put it under a load then the hesitation again. Compression is all equal around 120. fuel pump still looks good as well as the carbs. The fuel tank vent is wide open. The stator is puting out around 360v ac and wiring diagram is checked to be accurate. I don't think I am over propped with a 19p. It idles like a champ and starts even better. here

[messiklan]

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. here

[kosovito]

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.

[nina08]

The 2016 Yamaha V MAX SHO 115 is a mid-size outboard with extra juice.

[sizecocktail]

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. here

[jarlethaanthonyt]

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. here

[galeru]

Re: regency 22ft pontoon with 115 hp motor speed more

[Traktion]

If you have the performance toons with lifting strakes you should be able to do over 30mph. I haven't checked mine with gps, but the dealer said they took it for a test and hit 35 with low fuel and light load. Will try it later this summer myself. I know when it gets up on the strakes you can feel it pick up speed. Just curious, what prop do you have? Mine is a 13.75 / 15 and it hits 6600 at wot.

[Abn0rmal]

I may be interested in one next year, however I want something that i can cruise with at 24/25 mph. If 35 is tops then that would be great.
I will pm you here

[willyzg68]

Re: regency 22ft pontoon with 115 hp motor speed [links]

[bijenu]

The Nitro has a faster hull design, the Hell’s Bay uses more advanced construction to be lighter but doesn’t get the same lift, so viola, you get similar performance, illustrating the importance of the hull design. The Hell’s Bay outperforms it at cruising RPM, because of the weight and the small Spitfire prop maybe a little too small, slipping quite a bit. Either way, the engines swapped out would probably achieve about the same overall performance. Both should strive for running closer to the 6,300 range. Now imagine these engines on a small and light Hydrostream or little Checkmate Predictor. You could get them to run really well. [links]

[cartman]

Because of the popularity of our comparison articles, I thought it would be fun to do one for the best 115 HP outboards. An incredibly versatile power option for fishing boats of all kinds, small runabouts, small pontoons and almost any boat under 19’ really. There are 2 serious contenders here, maybe 3 if you include Suzuki but the Mercury 115 and Yamaha 115 are the leaders by far when it comes to specifications. For our purposes I want to look at the Mercury 115 Pro XS and the Yamaha 115 Vmax SHO version, the semi performance versions of these diminutive 4 cylinder four strokes.

[TopSoil]

With the standard 2.07 gearcase, the 115 ProXS turning a small diameter, 12.7”, Spitfire 19” at 6,000 RPM, the Z17 went 51.3. At 3,500 RPM it ran 26 MPH getting 7.5 MPG. As you can see, completely different boats, similar engines with slightly different gearing and they achieve almost the exact same speed. The Nitro is very heavy for its size and like the Marquesa is loaded with extra stuff, trolling motor, extra battery etc. [links]

[BitLex]

Let’s take a look at some tests knowing that this is about as close as it gets in an incredibly competitive engine class. Both are light, with the Pro XS being slightly lighter, 360 Lbs. vs 377 Lbs for the Vmax SHO. This is why I love this category, if you’re repowering an older lightweight performance boat, these are truly light engines.

[Golobulus]

How does the Nitro compare to the Hell’s Bay from purely a design perspective? It’s very different, here are the details; a 17' 4'' length, beam of 8' 4'' and a dry weight of 1,450 lbs. Although heavier and tested at 2,317 lbs, the Nitro has a more sophisticated hull, 16 degree deadrise and gets more lift from it’s design, with a pad bottom. here