Moderated Discussion Areas
  ContinuousWave: Whaler Performance
  Montauk with E-TEC 90

Post New Topic  Post Reply
search | FAQ | profile | register | author help

Author Topic:   Montauk with E-TEC 90
sail16 posted 07-01-2014 08:09 PM ET (US)   Profile for sail16   Send Email to sail16  
I just re powered my Montauk with an E-TEC 90. I went with a Stiletto 13-1/4 x 15 prop which seems to be a good match.

I salvaged the 13x19 OMC stainless prop from my old engine. I'm about to offer it for sale but wanted to get any opinions on whether there's any chance this would be an acceptable backup prop for my current engine. My sense is that it has far too much pitch to warrant keeping it as a spare.

Teak Oil posted 07-01-2014 10:03 PM ET (US)     Profile for Teak Oil  Send Email to Teak Oil     
I ran an aluminum OMC 13x19 on my Montauk with a V4 90 with decent results, but it was not optimum. The V4 is a very strong 90, not sure the 3 cylinder E-Tec would turn it quite as well.

It would be OK to use in a pinch, but it would not be optimal for a whole season

tedious posted 07-02-2014 07:44 AM ET (US)     Profile for tedious  Send Email to tedious     
What is your WOT RPM with the Stiletto? Remember that the cupping on the Stiletto will add 2" of effective pitch, and maybe a bit more. So if you're in the high end of the allowed WOT RPM range with the Stiletto, the your old prop (that's the old OMC SST, right?) will likely do fine as a backup.


Jefecinco posted 07-02-2014 09:46 AM ET (US)     Profile for Jefecinco  Send Email to Jefecinco     
For a spare propeller intended to get you home or to serve for a few days if your primary propeller needs repair I'd think your old propeller would serve you just fine.


thegage posted 07-02-2014 09:53 AM ET (US)     Profile for thegage  Send Email to thegage     
You don't say what your WOT is with the Stiletto.

I run the same Stiletto on my E-TEC 90 on my 16SL. IIRC the Stiletto is effectively a 17 pitch, and that would seem to be correct as it replaced an OMC aluminum 17 pitch prop with little change in full-throttle rpm. While the OMC 13x19 you have is nowhere near optimum, it could function as a backup--if by backup you mean to get you back to the dock one time when the Stiletto is damaged. I certainly wouldn't run it for any length of time as the engine would be way under ideal rpm.

John K.

sail16 posted 07-02-2014 10:14 AM ET (US)     Profile for sail16  Send Email to sail16     
WOT with the Stiletto prop is right around 5,050-- I believe that is pretty spot on the ideal.

I know I could answer my own question by seatrialing the spare prop but I don't want to go through the trouble if-- as I suspect-- it is far from optimal.

tedious posted 07-02-2014 12:23 PM ET (US)     Profile for tedious  Send Email to tedious     
Actually, you're right at the low end of the recommended WOT range of 5000 - 5500 RPM. You didn't specify what load you had on board, but if that was with a light load I might be looking at dropping down to a 13-pitch for your primary prop.

It doesn't sound like the old SST will be a good spare, although it would certainly get you back to the dock. However, with a stainless prop, carrying an on-board spare doesn't have a lot of value - any hit that will render the prop unable to get you back to the dock will probably disable the motor as well. Take that from someone who has been on board (but not at the helm) when a rock hit destroyed the lower unit and stainless prop - but it still got us back home.


jimh posted 07-02-2014 12:23 PM ET (US)     Profile for jimh  Send Email to jimh     
While there may be some difference in the pitch rating used by OMC and Stiletto for the two propellers, to think that the OMC propeller with a pitch of four inches higher will work like the Stiletto propeller is probably not a reasonable assumption. But the only way to determine if the OMC 19-pitch propeller is at all useful as an emergency spare propeller is by actually testing it. To change propellers is not a very difficult, tedious, or time consuming chore. Also, if you are planning to be able to change propellers at some time in the future when an emergency requires it, changing to the OMC 19 will be a good way to test your boat and its onboard tool kit. See if you have onboard everything you need to actually change a propeller. There is no point in carrying a spare propeller around only to discover you don't have the right tools onboard to install it when the actual need to do that arises at some unantipated place and time.
sail16 posted 07-02-2014 01:49 PM ET (US)     Profile for sail16  Send Email to sail16     
Tedious: the recommended WOT is spec'ed by BRP as 4500 to 5500. I assumed that dead center of that range is ideal-- do you have a different perspective?

JimH: I've got the tools and know how to do the swap-- before I burned the time, I wanted to know whether it was even reasonable. From what I have read here and elsewhere, I suspect my WOT would end up in the low 4k range-- it would get me by in a pinch, but probably better to sell it and pick up a spare that's more in spec.

bloller posted 07-02-2014 02:02 PM ET (US)     Profile for bloller  Send Email to bloller     
15 pitch was not enough and 17 was too much so I went with a Quicksilver in 16 pitch for my 16' Whaler 90hp E-tec combo. It is the same prop as the Mercury vengeance just adapted to fit the Evinrude gearcase
thegage posted 07-02-2014 02:04 PM ET (US)     Profile for thegage  Send Email to thegage     
The target RPM range for that motor at WOT is 5200, with moderate to heavy load, to assume that with a minimum load you'll be at the top of the range. Ideal check is with a computer hooked up since gauges are notoriously off.

John K.

sail16 posted 07-02-2014 02:18 PM ET (US)     Profile for sail16  Send Email to sail16     
thegage: Can you cite a source for your comment that target WOT is 5200?
tedious posted 07-02-2014 02:32 PM ET (US)     Profile for tedious  Send Email to tedious     
The specs for the eTec 90 currently show full throttle RPM range to be 5000 - 5500 RPM. That's off Evinrude's site, just moments ago.


thegage posted 07-02-2014 02:48 PM ET (US)     Profile for thegage  Send Email to thegage     
http:/ / www. etecownersgroup. com/ post/ correct-propping-procedure-for -an-etec-6491298?pid=1279238841#post1279238841

I have a service manual but can't check it right now to confirm.

John K.

jimh posted 07-02-2014 02:53 PM ET (US)     Profile for jimh  Send Email to jimh     
For information on the recommended optimum speed range of an E-TEC outboard engine, check this article in the REFERENCE sectioni:

E-TEC Recommended Engine Speed Range

I think you will find that this article is a concise, easy to use, and accurate collection of information about the recommended maximum throttle engine speed range and the optimum speed range for E-TEC engines. It is much easier to locate information from the REFERENCE article than to follow a lot of discussion and links in the thread that has been suggested.

Note that there is some variation in some models from year to year on the recommended speed ranges. I don't have data for engines made after 2013, but I suspect they are likely to be still in the ranges shown for 2013.

jimh posted 07-02-2014 02:55 PM ET (US)     Profile for jimh  Send Email to jimh     
There is not much difficulty in having all the tools needed to change a propeller, but the point of my mentioning this is to remind that you must have all of those tools on the boat if you are going to be able to install a new propeller at some future time and place when you're not working in your driveway.
sail16 posted 07-02-2014 03:14 PM ET (US)     Profile for sail16  Send Email to sail16     
Thegage: thanks. Probably splitting hairs, but there seems to be different answers from different official sources. The BRP site says full throttle range is 5000-5500 while the service manual says 4500 to 5500.

The link to the service addendum you posted says the *optimal* WOT range is 5000-5200.

tedious posted 07-02-2014 04:36 PM ET (US)     Profile for tedious  Send Email to tedious     
Sail, in answer to your question, I do have a different perspective - I like to prop so the maximum RPM, running as lightly loaded as possible, is up pretty close to the high end of the range, if not a tiny bit over. That maximizes performance over the widest range of loads - keeps your RPMs up in that recommended range even as you add people, coolers, supplies, and fish!


Teak Oil posted 07-02-2014 09:47 PM ET (US)     Profile for Teak Oil  Send Email to Teak Oil     
What speed are you getting with that Stilletto? You should be around 43 mph or so.

I would think you should be getting a few more rpm than that with that prop. Is your engine mounted all the way down in the blind holes, or does it have a small jack plate?

jimh posted 07-03-2014 10:39 AM ET (US)     Profile for jimh  Send Email to jimh     
I can save you about ten minutes of your life by excerpting the brief contents of the video (posted in the thread that is given in the link above that has been recommended as the source of information on the method of propeller selection). At about two minutes into the video, the narrator gives this advice:

Accelerate to full throttle, and check the engine RPM. The propeller should allow the engine to run near the midpoint of the recommended full throttle operating range with a normal load in the boat.

If you have less than the normal load (for instance, less people or gear than the customer will have), or, if you are testing on a cool day, the outboard should run near the top of RPM range. (The outboard will produce less power on a hot, humid day, because the air is less dense.)

For best results, you should try to achieve the engine's optimum propping point, which is a narrower RPM band than the wide-open throttle range

Note that the optimum range of RPM is not given in the video. To learn to optimum RPM range, read the article in the REFERENCE section. See

E-TEC Recommended Engine Speed Range

Find the optimum RPM range listed in the last column of the table.

If you find that you like to read low resolution rasterized images of this text as a JPEG file, you will find a link to this same information as rasterized JPEG images of text (posted in the thread that is given in link above that has been recommended as the source of information on the method of propeller selection) You can click on many thumbnail images of rasterized text until you find one that contains applicable information.

Post New Topic  Post Reply
Hop to:

Contact Us | RETURN to ContinuousWave Top Page

Powered by: Ultimate Bulletin Board, Freeware Version 2000
Purchase our Licensed Version- which adds many more features!
© Infopop Corporation (formerly Madrona Park, Inc.), 1998 - 2000.