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Outboards, hp and performance

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Scott1

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Hey guys, a little slow in this forum so just want to start a conversation and see if anyone has any major disagreements. I've messed around with props, motor height and ECM flashes. A few others on my lake also have and I've been involved with them. My thoughts below:

Many dealers don't have a clue about getting the top performance out of our boats or they just don't care. They seem to always mount the motor in the lowest position, if you let them know the prop they installed is 5 or 600 rpm short of expected at WOT with a light load, they think this is ok. It is actually only 'ok' if someone doesn't want their boat operating at best efficiency.

The biggest performance jump for the next step up in HP is from a 115 to a 150 HP engine. Those two engines are night and day in performance.

One thing I always cringe at is when someone asks will 50 HP really make that much of a difference and someone answers with "It will only be about 4 mph difference". The reason I cringe is I hope that person doesn't make a decision on that answer. The real difference is when the boat is loaded up. Example on a 250hp engine, if it runs 47 mph lightly loaded it can still run 44 or 45 mph with many people on board. as you drop down in HP range the difference is more drastic, especially if you are going from a 6 cylinder to a 4 cylinder. (Not talking supercharged engines)

I also cringe when someone says the 50hp won't be that much different because the weight of the engine offsets the hp gain. Are you kidding me? If the engine weighs 80lbs more, that is just the weight of a smaller child (my cooler ways that, lol). This answer needs to be put into context also. A 50 hp increase on a 150 hp engine is a 33% increase in power, that 80 lbs means almost nothing. On a 400 hp engine that 50 hp increase is only 11.76% more power.

For some of us, getting our boats set up for maximum performance is important, for others they really don't care. I would just hate knowing my boat could go an extra 5 or 6 mph if the prop was correct and motor height was correct. Just the OCD in me I guess :)

Just curious of other peoples opinions, experiences and if any of you really care about top performance from your engine.
 
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Agree on all points, although with respect to dealers and set up, without input by the owner it might be hard for them to fine-tune or optimize the engine height and prop. Some might want more holeshot for towing or load, while others (like me) are typically alone or lightly loaded and want straight line speed and fuel efficiency. I'm 2 holes up with a smaller diameter prop that loses some grip (slight cavitation) in tight turns especially when there are people up front. No problem, because of the gains elsewhere, but it might suck for another owner with a different use profile.

Owners also can be pretty uneducated and flaky, so the dealer might just play it safe with lowest mounting position and stock prop. I knew very little about pontoons prior to owning mine so I'd put myself in that category.

Last item I'll add, and I think this is what helps separate Bennington from the competition is there is this robust owners forum that can help with setup items. Where a dealer (and lets be real, all dealers regardless of make) falls short, owners groups can pick up the slack which is huge. Not to mention their engineering department has always been willing to respond to emails or talk on the phone. In totality I would say we have it a lot better than others!
 
It's not all the dealers fault . The dealers are provided a " suggested prop chart " from Bennington. Also most dealers take the buyer on a sea trial. My dealer changed the prop on my previous RCW 3 times at my request no charge
 
I hear you. Agree with most of it too. I never understand someone paying to get decent HP, especially on a tritoon, but not worrying about dialing it in (prop and Motor mount height) to actually take advantage of the potential performance for their intended use. And with the variety of dealers and owners out there, its just a lot of variance. Hence, I think that leads into dealerships setting them up conservatively (and generically) a lot of the time - unless the new owner is knowledgeable enough themselves to provide insight and guidance in that regard.
 
Jack M said:
It's not all the dealers fault . The dealers are provided a " suggested prop chart " from Bennington. Also most dealers take the buyer on a sea trial. My dealer changed the prop on my previous RCW 3 times at my request no charge
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I can see this point but even if the owner doesn't go on the see trial, you'd think the dealer would know if the prop is close or not when they do it themselves. Bring the boat up to WOT and see what the rpm's are at. I agree though, most of them probably go off the chart which is close enough for them.
 
My dealer put a Reliance prop on there, said it maxed out to 46 (which I believe) and was within specs for RPM range and called it a day.

So no arguments that the prop "worked" but it was a terrible choice for an F250 for my expectations and objectives. For some sandbar cruiser it might have been perfectly adequate.
 
Potomacbassin’ said:
My dealer put a Reliance prop on there, said it maxed out to 46 (which I believe) and was within specs for RPM range and called it a day.

So no arguments that the prop "worked" but it was a terrible choice for an F250 for my expectations and objectives. For some sandbar cruiser it might have been perfectly adequate.
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Yeah, this is my first Yamaha and reading through the threads and the Yamaha site it looks like the Saltwater series ll HP is the best for my 250 SHO. I'm sure an Enertia might be good also. I have a couple different ones spare I could try also.
 
I've tested the SWS 16 and 19, both were fine. The 19 had very good performance but ran out of RPM so just too overpropped to keep. I kept the 16 as my spare, and run a 17 Enertia as my primary. Part of the magic of the Enertia is it has more rake and this smaller diameter, which allows you to run your engine mounting a little higher.

If money were no object I'd run a hydraulic jackplate and really get it dialed while running.
 
Agree as well with everything said above. Some dealers are better then others at setting up boats.

Yamaha and other engine manufactures put out performance bulletins for a variety of boat manufactures which include engine HP, engine mounting height, which propeller is being used, weather conditions, elevation during testing (this is a HP / performance on outbaords at high elevation) fuel, number of passengers and gear, etc. Yamaha seems to be the most comprehensive of them all.

On the polaris site, Bennington has taken some of the Yamaha ones and posted them there but I usually go right to the outboard motor manufacture and look to get a "feel" of what model boat and HP is closest to my set up and then go from there.

When I had my Bennington, I played with motor height and prop pitch / diameter. Enertia was the best prop in my testing. I made slight gains over what the dealer had originally provided but it wasn't earth shattering by any means.

Here is one example of the polaris website and a them posting one with a Yamaha bulletin

Here is Yamaha's website for performance bulletins. Filter on Boat manufacture or filter on size of motor and search away.
yamahaoutboards.com

Performance Bulletins - Yamaha Outboards

Yamaha Outboard Performance Bulletins provide in-depth performance information on hundreds of boat and engine combinations. Browse Performance Bulletins here.
yamahaoutboards.com yamahaoutboards.com
 
Scott1 said:
Many dealers don't have a clue…
The biggest performance jump for the next step up in HP is from a 115 to a 150 HP engine. Those two engines are night and day in performance.
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I agree with much of what you have to say. My experience with Yamaha outboards is that going up from 115 hp to 150 hp feels more powerful than one would expect. That 35 hp increase represents a 30% increase in power. However the 150 motor has more than 50% increase in torque. Torque is what you feel. This is especially true with a loaded boat. However motor wieght can be a consideration. When I increased power on my boat I went with 115 hp power over 150 power. The wieght difference would of been equivalent to a heavy adult hanging way out back. When I was playing around with props I noticed that a lower pitch prop appropriate for a loaded boat felt more powerful under any condition. Dispite that powerful feel I selected a higher pitch prop to quantify my drag reduction modifications. Everyone has different ideas. Some of these ideas change and improve do to the knowledge gained from these pages.
 
Another reason why an upgrade to the Yamaha 150 engine is that noticeable and satisfying is because it's one of the few (or only?) engines that is UNDER rated. It has been said to produce 163HP.
 
Nautical said:
Another reason why an upgrade to the Yamaha 150 engine is that noticeable and satisfying is because it's one of the few (or only?) engines that is UNDER rated. It has been said to produce 163HP.
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There is a very similar comparison for the 115. The 115 rating is to cover any RPM in the desired RPM range. At peak power, at least some 115's have produced 125. Which, of course, supports rigging the boat to best performance for the particular individual use....meaning prop selection.
 
Nautical said:
Another reason why an upgrade to the Yamaha 150 engine is that noticeable and satisfying is because it's one of the few (or only?) engines that is UNDER rated. It has been said to produce 163HP.
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Not sure the standard Yamaha 150 falls into that category (but maybe it does) however most of the "performance" outboards will take advantage of the 10% rule of allowed HP. Mercury Pro XS. Yamaha SHO, Evinrude Etec HO, etc. mostly likely be in the 160-165hp as well for a rating of 150hp.
 
From my research, which may not be comprehensive, it seems the main performance difference between the standard Yamaha 150 and the Yamaha 150 SHO, is torque / hole-shot and that the top end speed is very close between the two models. Some reviewers recommended higher octane fuel for the SHO. However, the SHO graphics are preferred by some buyers (myself included). If it looks better, does it go faster and ride smoother?
 
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