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Author Topic:   montauk/mercury 90 2stroke prop suggestions?
littleblue posted 08-30-2004 04:27 AM ET (US)   Profile for littleblue   Send Email to littleblue  
I have a 81 Montauk w/ a 99 Mercury 90 on it. I would like some prop suggestions. I'm looking for something thats affordable, and in terms of performance, I would like to have good top end/cruising speed.

The prop on the boat now is some weird 4 blade composite w/ some gouges in one of the blades. (The boat is new to me) and when I test drove it, it seemed a bit slow...the engine was not trimmed but still, it seemed a bit on the slow side.) the

littleblue posted 08-30-2004 04:34 AM ET (US)     Profile for littleblue  Send Email to littleblue     
Are the props at west marine any good??
John O posted 08-30-2004 02:53 PM ET (US)     Profile for John O    
SS 13 1/4 x 19 or a 12 3/4 x 21 Alum on my 2001 mercury 75hp pushing a 1988 17' Hull

littleblue posted 08-30-2004 05:04 PM ET (US)     Profile for littleblue  Send Email to littleblue     
Where did you buy/how much did you buy it for? I went to west marine today but their props seemed kind of second rate. Any good and cheap online sites?

Also, all I need to replace the prop is a new pin right?

(By the way, I did a search and couldn't find any specific info for my engine. The only post I came accross was one reccomendation for a 12 3/4 or 13 1/4 (he wasn't sure which one) by 21.

So please, any reccomendations or links to some good infor would be greatly appreciated. Thanks.

John O posted 08-30-2004 08:03 PM ET (US)     Profile for John O

I bought 13 1/4 x 19 SS Rapture from them this month for about $243.00 including the new trim tab that had to be replaced for the different prop.

I am not sure of there prices on Aluminum but they were about 50 bucks less than most local dealers and about 80 bucks less than theft marine ( west marine)

800 573 5533

littleblue posted 08-30-2004 10:31 PM ET (US)     Profile for littleblue  Send Email to littleblue     
what kind of top end speed do you get w/ that prop? I was out on the boat today, full tank of gas (27 gal), 3 adults, 1 kid, 1 dog, top speed was no more than maybe 35-36mph.
John O posted 08-31-2004 12:38 AM ET (US)     Profile for John O    
I do not have a speedometer or GPS. I would say that the results you are getting now are decent under the described load.

I have a 28 gal tank and weigh 250 lbs. I imagine I am getting close to 40 mph, but again I have no way to verify.

I did cruise with Newt recently and he may be able to shed some light on our speed. We were both running a 21" alum prop.
Newt with a 2002 Merc 90 hp 2 stroke pushing a mid 80's Montauk and my boat with a 75hp 2 stroke.

jj69xxl posted 08-31-2004 01:59 AM ET (US)     Profile for jj69xxl  Send Email to jj69xxl     
I drive my montauk 17 with one yamaha 115 HP fuel injected to 4-stroke super and only approx. 8-10 L/h
newt posted 08-31-2004 11:14 AM ET (US)     Profile for newt  Send Email to newt     
As John mentioned, I ran a Mercury aluminum 21" pitch prop (on an '84 Montauk with '03 Mercury 90 2 smoke) with a top speed of 41-43 mph. Top speed was at 5500 rpms - NOT WOT. Lightly loaded, I think that engine could swing a 23" prop for even more top speed.

For less than $150 bucks, you can't go wrong with the Mercury (Don't waste your money on a generic prop) aluminum prop for all-around usage. I bought the prop at Boat US after experiencing blowout and excessive slip with the generic brand. I never did try a stainless prop, but other people on this site claim mid 40's as top speed with your boat/motor combo dialed in with the right stainless prop.

littleblue posted 08-31-2004 04:51 PM ET (US)     Profile for littleblue  Send Email to littleblue     
was that a 13 1/4 by 21?
John O posted 08-31-2004 06:28 PM ET (US)     Profile for John O    
12 3/4 x 21...12 3/4 x 21...12 3/4 x 21...12 3/4 x 21. ALUM
13 1/4 x 19 STainless Steel

Contact any prop shop and they will tell you what is best.

Do a search on this site and you will see the same answers we are giving you here.

Ultimately you may have to try several props to get the exact performance you want.

I would not skimp on a prop as Newt also suggests. This is what moves your boat. Junk will perform like junk.

montauk madness posted 08-31-2004 07:57 PM ET (US)     Profile for montauk madness  Send Email to montauk madness     
I have a '92 Montauk, '92 90 HP Mercury mounted 3 holes up and I run a 19 pitch Vengence s/s prop and hit about 43 MPH when I'm alone and fully trimmed out.


DeepSouthWhaler posted 09-01-2004 09:19 PM ET (US)     Profile for DeepSouthWhaler    
I have a 1986 Montauk with a 1993 90 HP Merc. The prop is a Merc Laser II 20 pitch. The boat with two people, two batteries, full fuel and gear will top out around 5300 RPMS and 41 mph. I know that all 90 HP Mercs after 1994 have a little more displacement. These motors may turn the 20 P Laser II prop faster.
Sammy posted 09-03-2004 03:06 AM ET (US)     Profile for Sammy  Send Email to Sammy     
littleblue -

There is a lot of information on this subject in the archives accessible by using the search function. I went through much of the previously posted material about two months ago when looking to replace a utility-type 19 pitch Michigan Wheel aluminum prop that came on a 1987 Montauk/1987 Mercury three cyl. 90hp that I bought in the spring.

I think it was LHG that said the Laser II 20 pitch stainless steel was probaly the perfect prop for this hull/motor combo. After reading his post and a number of very good articles by Clark Roberts, Peter, Bigshot and others I bought a used Laser II 20p in very good condition for $250. You could probably buy one cheaper on ebay if you are patient. New prices seem to range from about $380 to $530.

Performance improved significantly.

With GPS my numbers are very close to those reported by DeepSouthWhaler. With two guys (180 - 200 lbs.), one battery (soon to be two), lightly loaded and about 14 gallons of fuel the motor was turning 5500 rpm and hit 42.0 on a GPS unit that locks in the highest recorded speed. Light wind, surface ripple, vent holes wide open (no inserts), trimmed out and motor mounted one hole up - could probaly be raised one more. It's a little rocket coming out of the hole.

Last weekend on the Mississippi with two kids (80 & 125 lbs), three adults (125, 190 & 200 lbs,) a 65 pound dog, very little gear and about 16 gallons of fuel the top end rpms dropped to about 5200+. Did not have the gps along but speed and hole shot were very good and still noticeably better than with the previous 19 pitch aluminum and much less of a load.

Read some of the material in the archives. Just from this post John O, montauk madness and newt have reported good performance with other props. Then it gets down to your definition of affordable as well as how you will use the boat (cruise, ski, tube, etc.). Talk to a dealer about trying a couple different props. A good prop - the right prop for your use - will make a big difference in efficiency, performance and enjoyment..

home Aside posted 09-03-2004 09:11 AM ET (US)     Profile for home Aside  Send Email to home Aside     
I know absolutely nothing about prop size, pitch, or performance. I do know that the lower end / transmission will give before a SS Prop will if you hit something.
After reading many of the posts regarding this subject, I asked someone recently about the subject in regards to my 1982 Montauk w/1982 Evinrude 90. Basically my understanding of the answer was that in the smaller mid-range outboards the Prop size, pitch, etc doesn't have the effect on performance that it does on the bigger outboards.
I'd have to run out and look at the numbers on the prop I have on mine, but I know it is an Evinrude/Johnson aluminum, which probably came with the engine originally (Still in great shape and no problems I know of).
I got 41.7 MPH on GPS while running relatively empty with exception of me, gas, anchor, etc in St. Ignace with flat water this spring, and around 38 MPH loaded to the gills with full canvas up, on not so flat waters in August at the BWGLCC North Channel Rendezvous in August.
I see a lot of ink about SS Props as well as a lot of SS Props on Boats, Am I missing something here or is it really just personal preference ?


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