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ContinuousWave: Whaler Performance
Mounting TWINS on a Montauk
|Author||Topic: Mounting TWINS on a Montauk|
posted 12-31-2001 10:35 PM ET (US)
I was curious with all the threads about 70,90 hp Suzuki, Honda, Yamaha 4-strokes for Montauks that there didn't appear to be an argument posted for TWIN say 40 Yammies.. or the like.. I realize there would have to be an engine setback bracket, and TWO 4-strokes... so cost an issue... but if the set up could be done, assuming acceptable transom fit/stress could be designed.. two engines would give more margin for safety, trolling, etc..
posted 01-01-2002 12:12 AM ET (US)
Howdy Ontariomariner. I think twin 4 strokes would be much too heavy for a Montauk. Many people have experienced porpoising problems with over 300# on the transom, though others seem to be alright with as much as 360#. I think setbacks aggravate the problem.
Many years ago I encountered a Montauk at Bimini with twin OMC 50s, which must have come to near 400#. The boat was very stern-down and started to porpoise at as low as 25-30Kt. My guess is that they didn't have T&T and were set too far "out".
Red sky at night. . .
posted 01-01-2002 01:40 AM ET (US)
True, but some of the newer transom units profess to add some bouyancy to offset some of the leverage.. especially if you "stepped" it a bit to give a cleaner run at water coming past the hull trailing edge. I suspect you are right.. any other takers?
posted 01-01-2002 11:58 AM ET (US)
just my 03,
The engines will be way too heavy, the Montauk hull is over 20 years old. I have seen a Montauk with a 4 stroke Honda that the owner extended the transom by adding aft sponsons, wierd looking, added drag and probably would have been better off dropping to a smaller engine.
Also twins are inefficent, now before I hear from all the twin folks, they are a lot more inefficient that the same HP in one engine. Couple of good threads on this here too see the one by Clark several months ago.
posted 01-01-2002 12:52 PM ET (US)
The boat was designed for a single engine... and a kicker. Add a 6 or hp long shaft kicker, and you'll have a great package. Over the years (13 years in USCG search & rescue) I've seen too many folks do things to their boat that their boat wasn't designed for, often that led to trouble. In this case, as already noted, use more fuel, add more weight, take up more room on the transom and console (dual instruments and controls), double your maintenance, jury rig a steering system, double your fuel hoses, etc. Fun to discuss, but I don't think its worth the effort.
posted 01-01-2002 04:39 PM ET (US)
The thing I like about this forum is you can post a "trial balloon" and get some informed input... for that I am thankful. On the matter of a main engine and kicker... would you think say a 90 honda and smaller kicker would be too much weight?
posted 01-01-2002 06:12 PM ET (US)
Some numbers from catalogs... older catalogs at the bottom of the drawer. Honda 90 4-stroke 360-lbs. Honda 8 hp 4 stroke 80-lbs. OMC 90 hp 306-lbs (older engine). Yamaha 90 hp 266 lbs. Yamaha 6 hp 59-lbs. Looks like the 4-stroke combo is 440-lbs versus the 2-stroke 365-325-lbs. Quite a bit heavier. Looks like the 90 Yamaha and 6 Yamaha together, weigh less than a 90 Honda. I ran a 90-hp Evinrude and the 6-hp Yamaha. I also used a separate 3-gallon tank for the kicker, not the two 12-gallon tanks onder the pilot seat. Never a problem with weight. Remember, we often add weight to boats, but rarely remove weight (we always take more "stuff" than we need). By the way, the 6 hp could push the Montauk at 5+ knots.
posted 01-01-2002 06:26 PM ET (US)
Several months (?) ago I was considering the same and just for the sake of 'always trying something new' still think about it. However, after giving it much thought and especially after the following comments I decided against it. I do like my '84 but think it's better served with a single anyhow. [An Outrage (a 19 possibly w/twins) is coming into focus though soon...] One of the big stumbling points for me was that to keep the weight in check was to get them in the 30-40hp range but most, if any, didn't have tilt and trim in those ranges and I wouldn't consider it without. The ones that did have T&tT would have been too heavy IMHO. I would like to see someone 'bite the bullet' and do it anyhow just to see what it looks like.
posted 01-01-2002 07:27 PM ET (US)
I've seen setups with a 90/100 main and a kicker of around 9hp for a fishing rig.
If your concerned about the "getting back to home port" issue, another way to do it is to leave the kicker on the deck, wrapped and padded until needed.
Best - Don
posted 01-02-2002 10:48 AM ET (US)
You could do it, and maybe even on the normal transom. I had a 35hp OMC 2cyl that weighed 130lbs. Twins would be light. I wonder though if because they would be that close, they would probably cavitate. Would not even think of putting a bracket on a Montauk, not enough wood to mount it to.
posted 01-02-2002 12:18 PM ET (US)
A year or so ago I saw a Nauset with twin Merc 50's mounted on jackplates. Static trim in the harbor looked OK, and the twin Mercs looked pretty cool on that hull. I didn't have a chance to talk with the owner, but I think the standard 85-100 hp 2-stroke + a kicker (the set-up I have on mine) is a better choice. For someone that just has to have twins, a move up to the OR 18 seems like a much better way to go. Tom Byrum's OR 18 with twin Yamaha 70's (Cetacea Page 8)is a great example. I had a chance to pilot this boat last spring, and it is a fantastic configuration.
posted 01-04-2002 12:55 AM ET (US)
Hey Andy. I seen a Montauk with twins on it last year. I forget what size they were. I think they were 35 Yamahas. The owner said he loved it but he wished he had a little more speed. After owning twins on an 18 outrage for a few years now it would be very hard for me to go back to a single.
posted 01-04-2002 11:25 AM ET (US)
I was impressed with the accelleration and easy trim provided by your twin Yams. For convenience when trolling, I definitely like the twin set-up because it allows steering and throttle from the console without any funky linkages, tiller extensions, etc. By the way, how's the sturgeon fishing on the bay? I imagine its starting to get interesting with all the recent rains.
posted 01-04-2002 02:19 PM ET (US)
My montauk has a Mercury 100 hp (367#) and Yamaha 8 hp (87#). The transom weight is fine unless 2 people are sitting on reversible pilot seat. In that case someone rides up front (total of 4). This motor setup is great for maximum weight in boat and speed; and for trolling with the high thrust yammy. 8 hp pushes 1400+ pounds 6-8 mph depending on wave direction. Two batteries, motors, and tanks make the montauk a serious offshore fishing platform in 2' or less waves. With a 28 gal. tempo tank, boat has a range of 150 miles (3500 rpm) and 3 gallon tank allows 2 days of trolling with kicker. Great setup.
posted 01-05-2002 01:38 AM ET (US)
Sturgeon is just starting to takeoff. I caught too many last year and kinda lost interest in them. Was a great year for tuna and salmon. If you want to go catch a sturgeon come on over some weekend. May go to the farallons Sun if your interested.
posted 05-14-2003 12:24 AM ET (US)
We use a 1976 17' Montauk with two 50 hp evenrudies for surf rescues on the North Shore of Oahu. The twins fit well without any modification to the transom notch but do cause the stern to sit a little low at rest. Power is more than adequate, I don't know the top speed but she gets on plane right away. We mounted two 12 gallon tanks forward of the console. This gives us apout 8 hours opperating time, half of which may be at cruising speed and half at slow idle.
posted 05-14-2003 02:04 PM ET (US)
Somewhere in my files, I have a photo of a 15 Sport with twin Johnson 35's, with no transom modification at all! It was used as a tender to a 100' sailboat. I also remember seeing a guy with a Nauset powered by twin 2 cylinder Merc 40's. He said it didn't have enough power, and should have used the 4 cylinder 50's instead.
But to me it no makes no sense to power a classic 16/17 with twins.
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