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I am about to raise the height of the E Tec 115 on my 1991 17' Outrage. Whaler recommends the usage of the 2nd hole which would be the 2nd lowest height for the engine. From what I read in this forum most people prefer using the 3rd hole which would be 2nd highest position for engine. Right now the engine is mounted on the 1st hole, lowest mounting height. What I notice is my RPM at wide open is 5000, sometimes only 4800. I am using an aluminum prop. I don't mind changing out the prop but I want to make only 1 change at a time and that change is to get the motor mounted higher.

All things being equal what will I notice if I go the the 3rd hole versus the Whaler recommended 2nd hole? Is a higher engine going to necessitate going to a stainless prop?

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As you already know, all the way down is too low and Whaler recommends mounting it 1 hole up.

This description for mounting height is fairly standard:
http://www.whalercentral.com/articles...cle_id=106

Moving the motor up is fairly simple and can be a one man job although another person is helpful.

I would move the engine up and put the bolt in the 3rd hole from the top which would be mounted 2 holes up.

Your RPM's need to fall between the manufacturer's specification for WOT operation.

What size prop do you have now?
Pitch x Diameter

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What size prop do you have now?
Pitch x Diameter[/quote]

I am getting the motor mounted higher on Monday at which time I will get the prop specs. The boat is at its storage which is miles away. I am curious to know if rpm will increase with height adjustment. The way it is now one would think the prop is not the correct pitch/diameter, 4800 rpm WOT and 36 mph with 2 people onboard does not sound optimal, not from what I've read here.

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If a motor is too low, it is dragging and slowing the top speed down.
Sorta like throwing out a gallon bucket on a rope and wonder why the speed is slower.

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I owned a 1991 Outrage 17 for 7 years.

Your motor is definitely not running properly due to bad setup/prop.

Several owners of 1990-1995 Outrage 17 I, with a 115 hp motor reach 41-45 at 5400-6000.

The recommended WOT range for an E-TEC 115 is 5000-5500 with the sweet spot at 5400.

A fellow Outrage 17 I owner, JohnnyCW shared this comment on his setup.


cf: http://www.whalercentral.com/forum/vi...post_55432

I have read countless comments that E-TEC motors do their best at 3 holes up. This recommendation comes from actual Boston Whaler owners.

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I am using an aluminum 13.25" x 17 prop.

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A 17 pitch sounds right according to other posters.

You should be getting more then 5000 RPM so the motor being mounted low is the thing that is slowing you down at this time.

I know Montauks do best with the E-Tec mounted all the way up.
I am not sure about the Outrage 17' I models however.

I would start by raising the motor 2 holes up.
Your WOT RPM's should raise up.

If that doesn't do it, then it would be time to look at the prop in my opinion.

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I raised the motor up by 2 holes. I will test it soon to see how that goes. If all goes well I will consider spending for a stainless steel prop. What do you think that will give me?

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It is hard to state exactly the difference between an aluminum prop and stainless steel since the blade design is different.

Generally speaking stainless steel props are more efficient and durable. They will not suffer the same damage as aluminum.

Remember size and design is not universal across brands.

A Yamaha K series stainless steel 13.25x17 will not necessary perform the same as a Stilletto Advantage 13.25x17. It may be better or much worse.

We can help with specific brand, model and size. Ask if you have questions.

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It has been 3 months and I finally got to test my boat for the first time since raising the motor 2 holes up. I had the motor sit at its lowest position previously. I am happy to say I have the max rev at 5500 rpm and that got me 38/39 mph based on the gps reading. Now I am wondering if swapping out my aluminum prop to a stainless will further enhance the performance. What brand?

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Stiletto stainless steel

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Johnny CW runs a ETEC 115 on his Outrage 17, mounted high. His prop is a Viper 13-7/8" x 17"

cf: http://www.whalercentral.com/forum/vi...d_id=14026

On the E-TEC owners forum he reported 44 mph @ 5700 rpm

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I just purchased a Viper 13 7/8 x 17 stainless and will try it out when I take the boat out again but that won't be for a few months now. In the spirit of doing one thing at a time I will refrain from raising the motor 1 more hole to its maximum height. Thanks to those who responded over the past season as I was fiddling.

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Yesterday I installed my new Viper 13-7/8" x 17 prop for my first trip out this year. With a full tank of gas (32 gal) I was able to reach 5400 RPM WOT and 39 MPH. That is not much different than what I achieved with the aluminum prop, however I like how the boat accelerates, handles and pops out of the hole much better. The only thing left to try is move engine up one more hole to its maximum position. I have the boat in the water for another 10 days. I will decide after that.

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Good news but I think there is something going on.

Remind us what the motor height is? How many empty holes above the top bolt?

How are we measuring speed? Marine GPS unit? cellphone app?
Statue or nautical mph setting?
http://boatsafe.com/nauticalknowhow/m.../miles.htm

Are you trimming out the motor fully?
- Trim out till steering gets light, bow starts to porpoise then trim in a few bumps of the switch.

Weather conditions?

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Over the years, I'm sure all of you have noticed, as have I, that buyers of new E-tec engines are always looking for more speed, evidently not getting what they had hoped for. The answer has always been, correctly, to raise the engine and get a better prop. In the past, this has always been a Stiletto SS, a recommendation of Tom Clark. They are now off the market, and re-purposed as a higher priced line, called Turbo, I believe. So the BRP Viper seems to be the answer. This is an old 3 blade design from OMC days?

I would strongly recommend E-tec owers, and others looking for top performance, look at the brand new Mercury designed props for mid range engines, 75-115HP, the latest prop engineering available. The first offering was in a 4-blade aluminum called a Spitfire, for those not wanting to spend up for an SS prop. It is probably the best performing aluminum prop you can buy.

But the real news is the new 4 bladed Spitfire X7, made from the same material as the now famous, and top performing Enertia line for 150 HP and up. Mercury says this prop is faster, and performs better than their own Laser II and Trophy Plus, some of the hottest props available and previous performance leaders for years and years on mid-range engines. That is really saying something, comparing it not to others, but to their own top perfroming lines. Cost, delivered is $389 from jacosmarine.com., a great deal and the same price as the Laser II, currently the fastest three blade mid range prop on the market.

Owners of 75-115HP outboards, 2 or 4 stroke, should seriously look at these Spitfire X7 props. Expect to be seeing this prop on the new Montauk 170's with 90 HP Mercs rather than the Laser II currently being used.


https://www.mercurymarine.com/en/us/p...itfire-x7/

[Moderator Comment: Let's not digress into engine selection in this thread, rather stick to mounting height, prop selection and related issues for PR William. Discussion of the latest Mercury engines is encouraged in a separate thread.]

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My motor height is 2nd from highest. I have 2 holes above the top bolt. The speed is MPH, statue, not nautical miles. I am reading the speed off of my Hummingbird GPS/Depth sounder. I do have a speed wheel at the stern so I cannot ascertain whether it is a gps reading or a mechanical reading. Perhaps I can try a cellphone app. Today I was able to reach 5600 RPM WOT and 40MPH. 2 people onboard . I don't think too much is going on. I think I'm getting close to optimum.

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You are two holes up.

While you should go up at least another hole, you will be above the recommended WOT range which means considering another prop (Viper 19" or X of another brand) and that is a big exercise for a few mph.

What I want to see is photos of the boat and BC.

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I am 3 holes up. There is only one hole left to go higher with motor. Yes I will show you pics of the boat. BC is a great place for boating.

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Finn, I ran a host of props on my 4S 90HP merc. I installed a jack plate to play with the heights. It's a 17 Wahoo! So size and weight are near parody. I tried all of the Merc SS props. 18" Vengence ran best full submerged and runs 44.8 mph. The Laser II was labbed, and had trailing edge cup and thinned blades, it did not enjoy running until the prop was about 10% above the surface. It ran 46.5 mph. If you look at the blade design of the Laser II, it's basically a small ear chopper with an exhaust hub. In the merc catalog, it's classified as a semi-surfacing prop. In this situation, a standard blade design like the Vengence will be better all around prop. I'm not sure if merc props and Rude props are compatible, but I wanted to share that discovery with you all.

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I wonder if the dolphin tail affects the top speed.

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WOT = 5700
Top Speed = 39 MPH (statue), measured with GPS and Phone App
250 lbs of gear, gas tank 3/4 full, 2 people

As you can see I can move up one more hole to maximum height.

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If the motor is mounted high enough, the whale tail should be out of the water when at high speed, so it should not affect performance. Many dealers recommend those fins because their customers are getting excessive bow rise at takeoff; typically the dealer has mounted the motor too low. Win/win for the dealer, not so much for the customer! You may well find you no longer need the fin once you find the correct motor height.

Maybe I am missing something, but the full throttle range seems to be 5500-6000 (http://www.evinrude.com/en-us/engines/etec_v4/etec_115_v4) rather than 5000 - 5500 as reported earlier. I always like to be at the upper end of the range, as it tends to improve acceleration and gives you greater flexibility, such as when you are heavily loaded. So if raising the last hole gets you to around 5800 - 5900, perfect!

Yes, you could probably squeeze out another MPH or two by trying to find the perfect prop, but you've described the greatly improved handling you experienced with the Viper - to me that's more important.


Tim

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So do you guys blast around at WOT all the time?

I'm a cruiser happy puttin around at 3600 rpm,
the engine just hums there.
The fuel burns quickly over 4300,
and the engine's screamin at 5+k!
TP

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@ Tedious and @ Perichbrothers. I agree with both of you. I like cruising at no more than 4300 and handling is important to me. When I bought the boat 2 years ago it was so poorly setup for handling and speed I had to do some exploring. I was also suspicious that perhaps the boat is heavier than the spec. 1020 pounds because of a wet hull. I did not like how the previous owner plumbed the bait well. These are the reasons why I wanted to compare outright performance.