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Author Topic:   attention montauk owners
scottfarm1 posted 12-07-2000 09:29 PM ET (US)   Profile for scottfarm1   Send Email to scottfarm1  
I met Clark Roberts while fishing at mexico beach(super nice guy). As you know I have a 96 standard converted to a montauk with a 31 gallon seat tank with a 96 75hp merc. My console is a little higher than a standard montauk therefore producing more drag. First thing Clark told me was I needed to raise my motor two notches(1 1/2 inches)and install a doel fin. I was already getting 38 and 40mph by my garman 12 gps. I raised my motor two notches which positioned my cavition plate at 1 1/8 inches above bottom of boat and installed the doel fin. I tryed it out on lake seminole and got 44.4 mph on a downwind run and 42.3 on an upwind run and also increased my rpm between 250 and 300. With the doel fin it feels like it has power steering at plane as compared to before. You can tell the engine is not nearly as loaded as before. I'm running a 13 1/4 X 21 pitch propco stainless steel cupped prop. The boat planes much faster and slower. -- got rid of alot of drag by raising that motor --also---the power trim is truly power trim now- thanks for all the great advice clark----dennis
Hoop posted 12-08-2000 12:06 AM ET (US)     Profile for Hoop  Send Email to Hoop     
Scottfarm1, you raised your motor two notches! I was mentally prepared to raise mine one, but two! The proof appears to be in the performance results, though.
Hoop, San Jose, CA
jimh posted 12-08-2000 12:38 AM ET (US)     Profile for jimh  Send Email to jimh     
This is really interesting stuff.

Here I sit in Michigan, with the temperature in the teens, both my Whalers tucked away (indoors) for the winter, snow blowing and drifting in, and now I can fall asleep tonight thinking about moving the motor up a notch or two this spring on my 15-Sport!

Excellent! I thought I was done fooling with that boat, but now I see I was wrong!


scottfarm1 posted 12-08-2000 04:55 AM ET (US)     Profile for scottfarm1  Send Email to scottfarm1     
When I first raised my motor I e-mailed clark and told him that motor sure looks awful high. He said just do it. If you'll noticed the pictures of his boats his are this high too. Max rpm on my motor is 5250--before I raised the motor I was getting around 5000rpm or little over. Now I'm getting 5350. When your running wot and shut down the engine it glides much further because of the reduced drag. When you hit the trim with the doel fin on it really pulls the bow up. Nice to be able to run in 1 1/2 inch shallower water and motor will be fully operational with the boat fully swamped. I was hesitant to post this because of the speeds being posted. Most 90hp motors posted here are not getting this speed. dennis
Peter posted 12-08-2000 09:19 AM ET (US)     Profile for Peter  Send Email to Peter     

How is the high speed handling in rough water? When I bought my 18 Outrage years ago, the 150 that it came with was mounted at the highest notch. In rough water, the handling was a little squirley. After a couple of years of this I had it lowered by one notch. Speed was reduced by about 2 mph but the high speed, rough water handling improved signficantly.

Ponchee posted 12-08-2000 09:43 AM ET (US)     Profile for Ponchee  Send Email to Ponchee     
Before my Whaler days I owned a 27' Cougar cat 2 seater offshore speed boat.
It had 3 2.4 ltr V6 mercs

In order to race APBA (Offshore C class)only two were legal so off the center one went.

The boat actually went faster...
Although acceleration suffered it acheived top speed about 2-3 MPH simply because of less drag in the water.

We toyed with lowering and raising the motors because we had hull pickups to supply the engine with water and transfer lines from one motor to the next if the hull were lifted for lengths of timeon one side.....
Trust me it happens on a medium sized cat with over 700 HP.

The result was a rough water configuration with smaller pitched "fisher" round eared props with the motors lowered more than normal AND a smooth water cinfguration with the motors raised way up and a bigger pitched cleaver type prop.

Race conditions would merit the particular configuration.
The difference in top speed was from right at 92 to somewhere around 75-80. (If I remember correctly.

Problem is with the motors really high rough water performance really droppped because your hull will create huge air pockets in the water behind the boat and any prop will suck it the pocket right to it and stall the fwd motion of the boat. Once the props get aerated they have to be slowed dramatically to gain "traction" again.
The smaller pitched prop with the round ears would keep the nose of the boat wherever we wanted to put it allowing the boat to be driven at speed with considerable control you wouldn't think possible.
In rough water races there is very seldom places to open it up and approach high speeds. In those places you just had to ride it out and make up time in the rougher parts of the course.
It's just the opposite in smooth water races, which BTW get boring because once you trim the boat and get in position the hull wins or loses the race so less drag is a plus because momentum is rarely lost.

OK What's my point.... (Sorry for the long post)

You should know what your boat does with these different configurations. Find a happy medium and know that.... Yes, I can get it to go faster but it sure handles the way I like it too the way it is.
A good all around boat is much better for everyday use than a specialty boat.
Take it from someone who has owned one.

I bought Shakey's Boat it's running 42 MPH.
It's plenty fast(for me) but in fairly rough water it tends to find ways to cavitate. That's ok I just slow down when it's really rough. Besides that's all I can do at the time.

lhg posted 12-08-2000 02:26 PM ET (US)     Profile for lhg    
Since BW is now factory equipping the Merc 2 stroke 90's (same engine as the 75's) on Montauks, it would be interesting to see what operating height they are using. My guess would be one bolt hole up (3/4") for all around use. Mercury's prop book says that any outboard capable of 40mph should be installed so that the anti-cavitation plate runs 3/4" above the water coming off the hull. The maximum safe limit for this on recreational boats, as boat speeds increase toward 60, is about 2" to 2 1/2". After that, you will need special water intakes, or modified intakes, to avoid drawing air into your cooling system, decreasing water pressure, and burning out an upper piston. If you are running elevated transom heights, as is easy to do with a transom setback jack, a water pressure guage is highly recommended.
A standard SS "elephant ear" prop can be run about 1/2" high without undue slippage, but above that height a more aggressive surfacing prop should be used, such as a Merc Laser, Mirage, Trophy Plus, High Five, 4 Blade Offshore or Revolution series prop. Conversely, THESE props should NOT be run fully submerged. These new prop designs are changing the rules on outboard mounting heights, for engines 70HP and higher.
Hoop posted 12-09-2000 12:38 AM ET (US)     Profile for Hoop  Send Email to Hoop     
Hmmmm. Now I have to decide. Do I raise my 70 hp Evinrude four stroke one hole or two? And given that the rpm currently is close to max'ing out at 5500 rpm at WOT (spec is 5600 max), will I need a new prop if I raise the motor 2 holes. And it's almost always choppy here in the SF bay. Decisions, decisions.
scottfarm1 posted 12-10-2000 04:55 PM ET (US)     Profile for scottfarm1  Send Email to scottfarm1     
Just got back from Panama City Florida. Went 15 miles offshore in 3 foot seas. Motor performs great in rough water. Was running about 25mph and had no problems. Got back in bay--opened it up and got 45mph on light chop. I'm keeping my engine up. Combination of doel fin,cupped stainless prop and right height on transom. Weather was 75 degrees today, caught grouper, lane snapper, and trigger fish in 100 foot water. Perch or crappie biting good in lake seminole. Eat your heart out you northern guys. Dennis in florida
triblet posted 12-10-2000 08:54 PM ET (US)     Profile for triblet  Send Email to triblet     
Yesterday (Saturday), the Pacific was, for
once, truly Pacific. I firewalled the
throttle as soon as I cleared the breakwater
and left it there all the way to Lobos
Rocks, 30 minutes exactly. This was on
the open Pacific, not in some Bay. And
had 60' vis for both dives, seals playing with us, and a heck of a good time. REALLY
eat your hearts out, snow country

Chuck Tribolet

Keith Silliman posted 12-11-2000 06:18 AM ET (US)     Profile for Keith Silliman    
Spent last week in -10 degree weather installing a septic sytem at my Lake House. Eat your hearts out, you guys on the West Coast.


Clark Roberts posted 12-11-2000 07:06 AM ET (US)     Profile for Clark Roberts  Send Email to Clark Roberts     
I love being in a Whaler in the cold, heat, rain or shine! "Whalering" is a state of mind! Clark ... Spruce Creek Navy
bigz posted 12-11-2000 08:10 AM ET (US)     Profile for bigz    

Though this post and threads were about Montauk performance!

Humm -- maybe weather and location has something to do with it --- TZ

Whaletosh posted 12-11-2000 08:56 AM ET (US)     Profile for Whaletosh    
Has anybody tried a jack plate on a Montauk. This would seem to allow the most versatiltiy.
Rick posted 12-11-2000 08:51 PM ET (US)     Profile for Rick  Send Email to Rick     
On raising the motor hght. I'm new to power boats (long time sailor)but on my montauk it would require redrilling the bottom mounting hole as it is in a fixed position to a female threaded hole in the motor. Also, doesn't raising the motor put more torque and leverage on the transom (more stress). Seems a lot of trouble to get 2 MPH at top end.I have a 1988 Yamaha that turns 5200 at appx 43 mph fully trimmed (13 X 17 SS prop) Is this about average. Thanks for any info. (With no sail to trim, I'm lost, but it is nice on those hot summer days when there is no wind)
whalertim posted 12-11-2000 08:52 PM ET (US)     Profile for whalertim  Send Email to whalertim     
I spent a short while working on my whaler. It has been in the 40's all day, but its still fun working on the Montauk.
Imp posted 12-12-2000 12:26 AM ET (US)     Profile for Imp  Send Email to Imp     
Wish I could work on on my Whaler! between work and family, maybe next weekend Tom
whalertim posted 12-12-2000 07:17 AM ET (US)     Profile for whalertim  Send Email to whalertim     
It's hard to find the time to work on the Montauk. Between work and family, time is short, But thats alright. We will have her right for the spring.
scottfarm1 posted 12-12-2000 04:18 PM ET (US)     Profile for scottfarm1  Send Email to scottfarm1     
I apologize triblet. I didn't mean to strike a nerve. I probably wouldn't like someone suggesting I live in a less than desirable place either. Have never seen a seal. Now Keith Silliman really knows how to have a good time. LOVE MY WHALER Dennis
triblet posted 12-12-2000 07:26 PM ET (US)     Profile for triblet  Send Email to triblet     
HUH? Nothing to appologize about, and no
nerve struck. I was joining you in ribbing
the poor, frozen, short boating season,
northerners. Now, we both probably struck
some nerves up there.

Chuck Tribolet

whalernut posted 12-12-2000 08:16 PM ET (US)     Profile for whalernut  Send Email to whalernut     
Guys, don`t feel bad for us Northerners, were just saveing some fuel costs, and I know the EPA loves me for not polluting the water as my 75` 85h.p. Johnson is an EPA nightmare! Regards-Jack Graner.
JAC posted 12-20-2000 12:02 PM ET (US)     Profile for JAC  Send Email to JAC     
Although I didn't measure the individual improvements, my 16' Bass Boat increased both speed and performance with the change to a S/S prop with an attwood fin, again by lifting it 2 holes and significantly when pushing it back on a jack plate of 5". From begining to end , speed incresed from 46mph to 51-52mph, which is about as fast as I ever want to go in this hull style. The only peformance issue occured when lifting the motor on the transom. The set back of the jack plate moved the prop into virgin water, eliminating the prop slip problem and helped with handeling and trim performance.
By the way, the last trip with this little Whaler was into 3' seas out of Port O'Conner. It was a rough day but considering a limit of bull red fish, numerous spanish and a King mackeral of 25#, Crevale ranging from 20#-25# and several nice trout, all under blue sky's and 75 degrees... Just another day in Texas/Paradise.
How's the ice fishing this winter ?
chad posted 12-20-2000 06:55 PM ET (US)     Profile for chad  Send Email to chad     
Do you have a feel for the gain in shallow water performance with the 5" jack plate? I have talked to a man in Seabrook, Texas who recommended a 5" Bob's Machine Shop jack plate with a 2.5" raise, and his custom made stainless steel cavation plate. Claims a Montauk will plane within one boat length, improve steering, and provide a step to board the boat as well. Thanks, Chad
MikeC posted 12-21-2000 07:33 AM ET (US)     Profile for MikeC  Send Email to MikeC     
I have used Bobs stuff on all my boats and it is real nice stuff.I have used his aluminum whale tail's on my drag boat and my pleasure boats and they work great and look much better thatn those bat man looking things and they only cost about 39.00.His number is 1-800-966-3493 he has a lot of nice stuff in his catalogue.
Clark Roberts posted 12-21-2000 08:02 AM ET (US)     Profile for Clark Roberts  Send Email to Clark Roberts     
Chad, also check out the TH Marine Inc. ( "High Performance 8".. I prefer this plate over Bob's Machine MJ-5 because of the following: more set-back; single screw up/down adjustment vs. two for the Bob's; narrower than Bob's and won't block the transom drain holes as will the Bob,s; you will get more lift; price is about the same... I have used both and currently have a 15 with Bob's MJ-5 (manual jack - 5") and a 40 Merc... and a 21 with 135 Merc Opti and a TH Marine Hi perf 8".. both are fine pieces of eqpt.. happy jack-plate hunting... oh, yes, you may need a new steering cable with the TH if your present cable is a tight fit... Happy Whalin.. Clark... Spruce Creek Navy
Clark Roberts posted 12-21-2000 08:02 AM ET (US)     Profile for Clark Roberts  Send Email to Clark Roberts     
Chad, also check out the TH Marine Inc. ( "High Performance 8".. I prefer this plate over Bob's Machine MJ-5 because of the following: more set-back; single screw up/down adjustment vs. two for the Bob's; narrower than Bob's and won't block the transom drain holes as will the Bob,s; you will get more lift; price is about the same... I have used both and currently have a 15 with Bob's MJ-5 (manual jack - 5") and a 40 Merc... and a 21 with 135 Merc Opti and a TH Marine Hi perf 8".. both are fine pieces of eqpt.. happy jack-plate hunting... oh, yes, you may need a new steering cable with the TH if your present cable is a tight fit... Happy Whalin.. Clark... Spruce Creek Navy
lhg posted 12-21-2000 11:33 AM ET (US)     Profile for lhg    
I am a fan of the one piece transom units made by Springfield Marine, available at Bass Pro for about $275. These are heavy duty 1/2" anodized aluminium units, rated for all engine weights, and come in either 6, 10 or 12" setbacks, also with the single adjusting bolt with prop wrench. They bolt right into existing engine holes, and have about 4 1/2" of lift. I have been using these in the 10" setback version for some time on my 18 Outrage and find them very high quality. For any V-6 powered boat, I'd go with the 12" setback.
Barry posted 12-21-2000 02:27 PM ET (US)     Profile for Barry  Send Email to Barry     
Regarding jack-plates, is more set back better? Other than a nominal increase in price is there any reason not to go with a 10 or 12" unit? Does the amount of set back determine how much higher the motor can be raised? How much will I be able to decrease my draft with a plate?

I'm interested in one for my Montauk mainly for better skinny water navigation. My Merc 90 is currently set up about 1-1/2" and performs great.


lhg posted 12-21-2000 08:11 PM ET (US)     Profile for lhg    
From my experience, the greater the setback the greater the performance enhancement, as long as balance and weight distribution of the entire rig is not significantly changed.

A full fixed transom bracket, such as by Armstrong or B Bracket, gives between 26 & 32" of setback, but the hull must be long enough to accomodate pushing the engine weight back that far. That's why they generally recommend at least 20' for one of these. The 26" or greater setback achieved with one of these automatically allows for the engine(s) to be run 3 to 4" higher than normal, but with the anti cavitation plate still cutting the water at normal heights. This is because the water "swells" up as it comes off the boat transom. Then, as the boat increases speed, the water swells up less, and the engine has the effect of running higher, providing less lower unit drag. This is where the speed increase comes from. In addition, they tell me that setting any outboard back has the effect of increasing hull length by that amount, since that is where the "push" is coming from. I am convinced that any boat with a bracket runs smoother and handles the sea conditions better than the notched transom same model.

All of this same physics applies to the conventional transom jacks also, but with less differential effect because of the shorter setback. So if your boat will handle the engine weight pushed back, and most Whalers will, and overall length isn't a problem, I would always go with the max you can handle. Setback brackets also improve bow lift, reducing wetted hull for increased efficiency, speed and getting the wave action under the hull for less pounding.

I am absolutely convinced that these devices can improve your boats' performance and ride for a reasonable expenditure. The bass boat and go-fast crowd discovered this years ago.

andygere posted 01-02-2001 03:40 AM ET (US)     Profile for andygere  Send Email to andygere     
I finally had conditions for a clean permormance test this weekend, and here are the results:
'79 Montauk, '79 Johnson V4 85hp, 13.25x17 aluminum prop, motor mounted in top hole set (lower unit as low as possible), Whale Tale
Load: 2 adults, 22 gallons of gas, 2 batteries, 15 hp kicker, fishing gear, cooler, ice.
Results: 37 mph on the GPS @ 5100 rpm WOT
tweaking the trim was good for 2 mph

RPMs seem a little low, but otherwise I'm pleased with the performance, even if it is a bit slower than similarly equipped Montauks. Also, boat has a great holeshot, leaping up on plane very quickly. Any thoughts on the missing 400 rpm? Is this typical for a "vintage" motor?

compounder posted 01-02-2001 04:05 PM ET (US)     Profile for compounder  Send Email to compounder     
I see you mention a 15 hp kicker on your Montauk. Do you know what the weight of the 15 is? Do you have it on a bracket or mounted directly on the transom? I am considering using a Nissan 15hp two-stroke, but am concerned about the 85# weight. Does the weight of the small motor cause your Montauk to list to that side at all? Thanks.
andygere posted 01-02-2001 04:29 PM ET (US)     Profile for andygere  Send Email to andygere     
I'll check the shop manual to be sure, but I recall the motor weight to be just under 100#. It's mounted on an OMC scissor bracket that uses a spring assist to raise the motor up from the "run" position. The boat does not list at all, and the 15 hp pushes the boat as slow as you'd want for trolling, and at a good clip (8+mph) for those "get you home" situations. I don't think the extra weight is a concern. For fuel, I have it rigged to run from the twin 12 gal tanks, with a Precor filter/seperator that has dual fuel line outlets. This eliminates the need for an extra tank. If I were setting up a new boat, the only change I would make is setting the kicker up with a remote throttle/shift. I've seen this set up with a dual stick Morse binnacle control. It's no problem steering using the main engine as a rudder, but when you hook up with a fish (or the bottom, more commonly) it's a mad dash to the stern to reach over and pop the motor into neutral.


compounder posted 01-03-2001 10:43 AM ET (US)     Profile for compounder  Send Email to compounder     
Thanks for the reply Andy. I have the same OMC bracket. One the subject of fuel supply, I too have a Racor filter setup and plan to just switch the fuel line to the kicker if needed. However, I am a bit paranoid because of fuel problems in the past. The only no-go type situations I have encountered were fuel related, so I also carry a separate 6gal tank with separate fuel line to run the kicker on and to use as a back-up supply for the main engine.
andygere posted 01-04-2001 01:56 AM ET (US)     Profile for andygere  Send Email to andygere     
Interestingly enough, I just purchased a 6 gallon tank and separate fuel line for the same reason. For offshore trips I'll put fresh gas in it and bring it along. For inshore trips, I'll probably just bring the spare fuel line.

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