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I put the 90 horse etec on my old '97. I'm not breaking 17 Kts with a 14x13 aluminum prop.

I was a bit dismayed that with ballast in and out I'm maxing at 4500 rpms.

In short, I'm going to try a 14x10, which may not increase my speed but pick up my rpms.

advertised 24 mph my @$$.

P.S. will also weigh my boat when I pull it next weekend; but I guess loaded she's 3300 W/o ballast.

What's everyone else getting - -and with what motor / prop?

-Gaz

The best top speed I ever got was 19 MPH with a 50 HP Honda 4 X 11.4 X 9.5 Solas prop. This was at the beginning of the season with a fresh waxed hull, light load and seas rippled, low to no wind and minimum current. Conditions were ideal.

At 800 feet with a Tohatsu 40hp I get about 13 mph. At 7500 feet I get about 11 mph.

BB

E-Tec 60 at 5400 RPM -I do about 15 - 18 knots per hour in Pacific Ocean without ballast. I think I have a 14 inch prop. Last trip was with 180 pound buddy, 4 steel scuba tanks, and good amount of scuba gear.

Sounds like you are overpropped Gazm....whats the ETEC recommended WOT range?

I think that it will help if in these conversations everybody use knots for speed since nautical mile is a bit longer than other mile. There is a lot confusion because of that. As far as I remember Roger (and some other boats or motors manufacturers) is advertising his speed in miles per hour which is 0.869 nautical miles per hour or knots. Advertising trick, it is a bigger number in mph than in kt. For example your advertised 24 mph is 20.855 kt. You might be close to that with different prop.

If everybody use the same measuring unit it will be easier to compare results with different motors or props. It will be appropriate if everybody use knots, we are sailing here. Everybody agrees?

I am out of this league anyways with my 30HP 2 stroke Nissan and unmarked aluminum slightly damaged prop. Top speed w/o ballast dropped to 9kt with addition of two deep cycle batteries and 20 gallon fresh water under the v berth. With ballast i am at 6.5kt for 5 minutes until half of the ballast is empty and than it start picking up.

Zoran

15.6 kts with 05 M 50 HP Merc BF. Prop was dealer installed #'s ??

Yes Catigale,

I agree with you; I was overpropped. With the 14x10 I got my RPMs up to 5200 in slight chop with a brief top speed of 16kts.

The motor sounded much better with this prop. I was begining to think I was running on two out of three cylinders until this long overdue prop change.

I'm hoping to change out the 14x13 for a "big dog eared" 14x10. - & then pull my boat for the season

Thanx for da #'s guyz

Gazmn Im sorry but its hard for me to believe that you are running almost twice the hp as most macs but get less performance. Either you have something wrong with the engine or whatever.

If what you say is correct then the motor needs to go back to the shop and have it checked. from what I have seen and read running a 90hp on the mac should give you numbers of least 25 mph or 22 knots. with out ballast. My 50 four stroke suz gives the same numbers as yours.
This cant be right and as Im looking into an etech 90 soon I would like to
get this straight in my mind. So Those running anykind 90hp on X or M
what are you guys getting in numbers? And that etech 90 should sling a 13 inch pitch prop with no problem reaching rpm range of the engine.
5500 or so without ballast and 4900-5000 with.

I think there a misunderstanding in the prop area.
the pich of the prop determines in ideal situations how many inches the boat will move for each turn of the prop. The more hp you have the
more pitch you can run. Also take into consideration that the higher hp engine will turn a larger blade. But a larger blade will not give you more speed only idealy less slip. If your motor is turning anywhere near the rpm max with the current prop you are running then going to a lower
pitch prop wont speed you up, it may even slow down.

a Mac is compared to a pontoon boat and we are trying to prop it that way.
but once the mac gets on plane there is no comparison. Now what we have is a planeing boat with a small hp outboard. what that boat needs is more hp and more pitch to perform.

so in the case of the etech 90 above less pitch slows the boat down.

what we are tryng to do with the mac is get up on plane and be able to use less hp to maintain that speed. around 15mph. In other words if you
have to use every ounce of hp your motor creates to just get on plane
then your going to need all the hp to keep it there. A 90hp engine should without breaking a sweat put the mac on plane and then move the boat at
17mph where you can actually back off on the throttle to maintain that speed. and in really calm water should be able to push the mac at much higher speeds the a 50hp.

I see etech 50-60s pushing the mac at max rpm running a 14x13 3 blade prop with decent speed. Out of the hole they may be a little slower but are able to get to max rpm. I think a 90 etech should be able to sling a 14 inch pitch prop and get into the high rpm range.

the 90 above must be running on two cyl. Because the performance is the same as a 60hp.

So in the case above if you really get the numbers your talking about I wouldnt waiste money on new props I would go to the dealer and find out whats wrong with your engine.

I agree with you Aya.

I think there's something wrong, like I'm running on two rather than three cylinders.

I brushed the bottom clean while in the water. and while happier after the prop change. I'm still not sure I'm in the clear.

Sadly, I have to pick up my boat by the 29th. The wind is high with a lot of chop lately and not going to change. i'm going to call my instlaller and another Evinrude dealer in the area. and see if i can get a body down on Wed, my next available day.

I haven't been greatly impressed with my dealer support.

Will keep all posted. Thanks for your .02


Regards,
Gaz

3 cyl. at 90 hp minus one is 2 at 60? I wonder...
Check the compression and buy a spark plug tester and see if its fireing on all cyl. pull the plugs and see if ones fouled.. New etech will run at 25 parts of gas to 1 part oil, when broken in will then run up to 100 parts to one or more . But thats a lot of oil to gas at first and you could have fouled a plug easy. So cheap check would be to pull the plugs and change them if they are oily.

another trick is to start the engine (in the water or hooked up to a hose)
place your hand on each cyl. as it runs ( it will be warm but wont burn you) all cyl. should be warm if one is colder then its fouled or not getting fuel.

I know evinrude says no break in and no service for 3 years but
frankly I dont think its a good idea to run spark plugs in an outboard
2 or 4 stroke for three years. But the 2 strokes do burn oil and will foul
even a high tech etech.

I have an Evinrude 60HP. I get a solid 20 mph solo with no ballast. With 3 crew and I and about 500 pounds of coolers and camping gear I held on to 18 mph crossing to Catalina, 29.5 miles. I never see any smoke, but she does roar at WOT.

06m, 60 etec . 2 people, full ice chest and normal other equipment.
I got 18mph yesterday on Lake Ponchatrain. Don't remember dealer installed prop pitch.

Nick

Suzuki 70 - 26M - 21MPH (>18 kts) on GPS.

Conditions permitting, 2002 X w/ 50 hp Suzuki 6000-6800 rpm, prop?

No ballast, witha payload of aprox 800lbs incl crew:
16.5 knots/ 19mph avg top speed, cruise 15 knots

With ballast, and same payload:
14 knots/16.1 mph avg top speed, cruise 12.5 knots

I do a lot of 30 to 65 knot runs from San Diego to Catalina & Newport, and when I go under power it is generaly at WOT, my Suzy seems to love to run that way.

Redline is 7000 rpm, I would love to get 200 more rpm, but I'm probably at optimum with my prop. I can't read the markings on the prop so I don't know what I've got.

Ric K