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  Performance of new Montauk 17?

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Author Topic:   Performance of new Montauk 17?
whalerron posted 08-19-2003 11:16 PM ET (US)   Profile for whalerron   Send Email to whalerron  
My friend just bought a new Montauk 17 with a 90 hp 2 stroke Merc mounted on the tranny. He is seeing about 34 mph with the boat and the motor sure doesn't seem like it is powerful enough for the boat. Does anyone have any experience with this combination and if so, what kind of performance are you seeing?

thanks,
ron

SSILVER posted 08-20-2003 12:43 PM ET (US)     Profile for SSILVER  Send Email to SSILVER     
1981 Newport w/ 1980/1981 Merc 90. 27 Gallons of fuel 2 battery, me 200LBS, slender wife, 2 kids 100lbs +- Mich Vortex 17 pitch or Merc OEM 17 pitch. Engine mounted all the way down, cheap stingray tail fin at 5K RPM's 37/38 GPS. Riding solo or w/ one kid not much diffrence 38/39 maybe 40. Using a Garmin GPS12. Thought about mounting the outboard a bit higher but its using the mid section from a 1978/79 Merc. 90 which does not have diffrent mounting holes and has the clamps which tighten down on the transom. I had to switch mid sections on the outboard because the original one was cracked. When I mounted it on the boat I had to fill 2 or 4 transom holes I forget w/ dowls and west epoxy then gelcoated them over. Currently is held to the transom w/ 6 bolts and the two screw clamps common to smaller outboards. I have read raising the outboard up some can give you some more RPM's. If I had known this before I had drilled new holes I would have experimented more. From what I have read sounds like I could gain a couple more MPH if it was really tweaked but would also loose bite in rough water. With that in mind I am leaving well enough alone. Did not consider a SS prop because of the costs associated w/ lower unit repairs if I ever hit a log etc... verses replacing a $120.00 Alum prop.

Sean

Bigshot posted 08-20-2003 12:56 PM ET (US)     Profile for Bigshot  Send Email to Bigshot     
Sean....no matter what prop you have, if you hit something hard enough to break gears it will break gears. I have ONLY used SS props and(knock on wood) never blown a foot and I have done some serious dredging in my time.
SSILVER posted 08-20-2003 01:47 PM ET (US)     Profile for SSILVER  Send Email to SSILVER     
Your lucky Bigshot!

I just bent a blade on aluminum one two weeks ago. I remember talking to a Guy named Barry on this site a while ago who ran aground and busted up his lower unit pretty good using a SS prop, can not say for sure an alum prop would have saved his lower unit, but it would have had a much better chance of surviving if it had Alum prop. I have heard of many folks using Alum props for that very reason and am pretty sure thatís touted as a feature for those comp props, loose a blade not lower unit or outdrive. I am not saying SS props are bad or anything like that, just stating the fact that Alum props will give your lower unit/outdrive a better chance of survival if you hit something.


Sean

Barney posted 08-20-2003 04:14 PM ET (US)     Profile for Barney  Send Email to Barney     
Whalerron, You say this is a new boat, so it's a 2003/04 170 Montauk? If he is seeing 34 MPH at WOT, seems low for sure. The new Montauk should see higher speeds, greater than 38 MPH. Something is wrong. Jim
whalerron posted 08-20-2003 10:47 PM ET (US)     Profile for whalerron  Send Email to whalerron     
The boat is new and so I guess this post belongs in a different place on this forum.

It seems slow to me too and I was hoping somebody would tell me what prop they are using and how far up their motor is mounted. I would have thought that Boston Whaler would be shipping the 90 Mercs in a standard configuration for their Whalers so that things were already setup perfect.

But, will a 2003 Montauk see 38mph with a 90 hp 2 stroke merc on the back? The boat is almost twice as heavy as the older style boats.

- ron

BOB KEMMLER JR posted 08-20-2003 11:26 PM ET (US)     Profile for BOB KEMMLER JR    
Ron did you end up showing him what the old Minot can do?
Barney posted 08-21-2003 07:28 AM ET (US)     Profile for Barney  Send Email to Barney     
whalerron, My 4 Stroke 170 Montauk, 2003, will do 38 MPH with the bimini up. Other people here have reported higher speeds on that boat. The 2 stroke should do better than that. Jim
bsmotril posted 08-21-2003 10:38 PM ET (US)     Profile for bsmotril  Send Email to bsmotril     
Everytime I see a post like this the first thing I want to know is how are you measuring your speed? GPS, Fishfinder Paddlewheel, or Pitot tube speedometer. If anything other than GPS, I would remeasure with a GPS to get a truly accurate speed. Pitot and paddlwheel speedometers can have big errors until they are calibrated against a good speed source (like a GPS). Even then, they are only accurate in a certain range where calibrated, and not accurate across the speed range.

If you are using a GPS, first check to see it is displaying speed in Miles Per Hour versus knots. 35 Knots is around 40mph. Also check to see if you have a GPS setting for averaging=slow,fast,normal. If set to slow, it could take the GPS a minute or two to display the Wide Open Throttle speed.

BillS

whalerron posted 08-21-2003 10:56 PM ET (US)     Profile for whalerron  Send Email to whalerron     
The 17 is my friend's first boat and he is getting the speed from a speedometer. I guess I need to go out with him and see what my GPS says.

Bob, he just spent 20K on the boat and I really don't want to make him feel bad! Right now, my Minot with that new Johnson 90 on it will run circles around his boat! But, that's not something I would do to a friend who is out in his new boat.

Is anybody out there running a 2 stroke merc on a new montauk? If so, what speed are you seeing and what prop are you running?

Barney posted 08-22-2003 07:36 AM ET (US)     Profile for Barney  Send Email to Barney     
whalerron, Suggest moving this to the Post Classic Forum, use New 170 Montauk 2 Stroke Performance Question. Maybe someone will pop up. Or use that title or something like it here. There are some people on the forum with that configuration. Jim
newt posted 08-22-2003 11:37 AM ET (US)     Profile for newt  Send Email to newt     
I am running the Mercury 2 stroke 90 hp on my '84 Montauk with a 21 pitch aluminum Mercury prop. I get 42 +/- mph, and the engine is NOT raised up to where it should be. That speed is at 5500 rpm - not WOT. My guess is that a 23" pitch prop would give me even more top end when lightly loaded. (The Mercury website prop calculator suggests a 23" pitch prop).

I know the new Montauks are heavier with a deeper 'V', but I believe the max rating is still 100 hp, and can't imagine that you would lose 8 mph over an older model with the same engine.

What prop does your friend have?

Perry posted 08-22-2003 01:11 PM ET (US)     Profile for Perry  Send Email to Perry     
newt, if 42 mph is not at WOT, how fast does it go with the throttle all the way to the stop?
newt posted 08-22-2003 05:05 PM ET (US)     Profile for newt  Send Email to newt     
I don't know. The few times I was trying to check max speed, I never ran over 5500 rpms (redline for this motor). Having dropped over $6k on the engine, it wasn't important enough for me to find out what a rod blowing through the engine block would sound like!
Sal DiMercurio posted 08-23-2003 12:55 AM ET (US)     Profile for Sal DiMercurio  Send Email to Sal DiMercurio     
That speedo is way off, or that engine is sick.
My good friend Tony has a 2,000 Montauk with a 90 Evinrude FICHT & he's running right at 45 mph, this I know for sure because I ran right along side of hiom & his sonar & gps & speedo all read the same as mine, 45 mph.
The Montauk isn't the fastest hull of the breed, but that Merc should run equal to the Evinrude if not faster [ higher gear ratio ].
I think you will find he's running real close to at least 42 mph.
Sal
Moe posted 08-25-2003 11:14 PM ET (US)     Profile for Moe  Send Email to Moe     
Here's a link to the 170 Montauk article in the reference section:

http://continuouswave.com/whaler/reference/170Montauk/

Here's the Cetacea article on Tabasco's early delivery 170:

http://continuouswave.com/whaler/cetacea/cetaceaPage58.html

Here's the forum replies to the above:

http://continuouswave.com/ubb/Forum5/HTML/000107.html

As mentioned, you'll find a lot more on the 170 and its speed in the Post-Classic forum, and you can do a search of all forums from the Continuous Wave home page. I've seen speeds as high as 43 GPS mph reported.

Hope this helps,
--
Moe

jmorgan40 posted 08-28-2003 06:08 AM ET (US)     Profile for jmorgan40  Send Email to jmorgan40     
Ron,
I have a 1986 Montauk that I picked up in June. I upgraded the engine to a rebuilt 2000 90hp Johnson 2 stroke. (Had a '86 70 hp). With myself, wife, and two teens and 27 gallons of fuel, I get about 38 mph. With just me and my boy I can get about 44 mph under perfect conditions. On a bad day about 40 - 41 mph. I picked up a few mph with the new stiletto 13.25 x 17 prop. There were some people on the site here that were a great help in the prop selection. Different engine but you should do a little better then current numbers

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