Yamaha 70 on a Montauk? - Moderated Discussion Areas

  ContinuousWave
  Whaler
  Moderated Discussion Areas
  ContinuousWave: Whaler Performance
  Yamaha 70 on a Montauk?

search | FAQ | profile | register | author help

Author Topic:   Yamaha 70 on a Montauk?

bdb posted 08-02-2001 06:12 AM ET (US)
Anyone running a 70 2 stroke Yamaha on a Montauk or other 17? What can you tell me about performance? (starting, idling, cruise, top end)
Thanks, a curious Harpoon Harry
Macman posted 08-04-2001 11:10 AM ET (US)
Harry, I have a 96 70 Yam on my Montauk. I bought the boat late last season. I am very happy with it. I can't give you performance specs,as I am still learning my GPS. Top end (with aluminum prop, don't know the pitch, 17?) is about 31with three passengers (apprx. 500) It trolls at about 1.5 to 2.5, depending on conditions. Starts with one turn, and runs quietly. Very reasonable gas and oil consumption.
If I were to repower, I would go with a 90, as I would like the higher top end on occasion.
I just got back from a week on the lake, were we cruised about( 4 adults, 3 kids), went tubing, and fished for salmon. It performed flawlessly on all fronts. It pokes around at headway speed especially well.
I would be curious to hear from other 70 owners as to top end. I suspect that a new prop might improve the performance.
My mechanic told me that the engine was his personal favorite...and that I could plan on having it run for a long time.
Bigshot posted 08-04-2001 02:55 PM ET (US)
You should be in the upper 30's with a 70 with no load. A ss prop usually adds a few mph, no flexing of blades.
bdb posted 08-05-2001 07:23 AM ET (US)
Thanks Macman.
For what it's worth I'm currently running an '86 Evinrude 70. Generally, with a couple of people aboard, I top out in the low 30s. Fastest ever was 36 with me, 20 gals of gas, beverages and ice, the dog, and her tennis ball...in a light chop. That's at 5600rpm, 13.25 x 17 stainless from Cabelas.
Anybody else have any Yam 70 info?
Harry
Clark Roberts posted 08-05-2001 09:33 AM ET (US)
I have had a montauk with yam 70 and four with yam 90's... here's my experience: Yam 70 performance was almost as good as the 90. The 70 was quicker to rev and got great mileage.. toped out at around 37mph... the 90's would run 39-42mph and all with 15" yam stailess prop... non would swing a 17". If I had to run either , I would choose the 70! Just one man's opinion! Clark.. Spruce Creek Navy
Alioop posted 08-05-2001 01:07 PM ET (US)
I have ran a 70hp yamaha's on my boat for 17
years. The performance for me has been very
satisfactory,I can get 36 mph with a light load and 34 mph with my usual load(2 people,fishing gear,28 gals.fuel).I puchased a new 86'and ran it for 14 years and found a deal ona left over 98'last year and the 98'is even that much better than the 86'due to the engine computer. I ahd thought of going to a 90 hp but have always had 70 hp on boat since new(1977)and did not want to change the boat.
bdb posted 08-06-2001 07:39 AM ET (US)
Thank you gentlemen.
I sure appreciate the opinions and reports.
Mark D posted 08-06-2001 09:07 AM ET (US)
Whats the best pitch prop for a 70 Evinrude on a 17' Montauk?
bdb posted 08-06-2001 04:23 PM ET (US)
Like I said above, I'm running a 17 at 5600rpm. Operating range is 5000-6000, so I'm right in the middle. However, there would appear to be room to go to a 15.
In my case the numbers are the same for both aluminum and stainless.
Macman posted 08-06-2001 09:19 PM ET (US)
Clark...just out of curiousity...did you have a Doel fin on your 70 Yam? As I recall you are a fan of this set up, with the motor raised one hole. What think ye?
Clark Roberts posted 08-07-2001 07:49 AM ET (US)
Mack, yes, I had a doel-fin on the 70 Yamaha and can't remember how high I mounted the motor!??? But I know it wasn't in the lowest position. Clark
Whalerdan posted 08-07-2001 08:00 AM ET (US)
Clark, do you think this setup would put a wakeboarder up? I find a wakeboard to be much easyer to pull up than a skier.
Whalerdan posted 08-07-2001 09:06 AM ET (US)
Does anyone know what the real horsepower output is for the yam 70 and 90?
Bigshot posted 08-07-2001 11:02 AM ET (US)
it is 70 and 90 respectively. People mistake HP for torque. The 90 Yamaha is 90hp but lacking in cubes compared to a v-4 it has less grunt. Hp dictates what it will do and torque says how fast you will do it. I am completely happy with my 90 Yamaha and I had a 115 Johnson on a montauk. With 4 adults and gear, etc, she pulls right out of the hole without tucking in the engine. I am the happiest with the weight and gas savings. A 70hp would be fine but for the few hundred I would hate to regret it.
Macman posted 08-07-2001 06:47 PM ET (US)
An update.....went for a 50 mile cruise today in all sorts of conditions. Chop, calm, 3 ft groundswell, you name it. With 5 people (apprx. 750 lbs) plus gas ( 19 gals), at 4100, the gps was reading 21-23 knots. I will not know my gas consumption until I fill the tank tomorrow. I suspect about 10 gals.was used. A great day on Casco Bay!
bdb posted 08-07-2001 09:46 PM ET (US)
Thanks guys...
The feedback is fantastic, and just what I needed to hear/read. It all bears out my feelings that the yam 70 would be a great general purpose Montauk motor.
Happy Harpoon Harry
bdb posted 08-07-2001 09:46 PM ET (US)
Thanks guys...
The feedback is fantastic, and just what I needed to hear/read. It all bears out my feelings that the yam 70 would be a great general purpose Montauk motor.
Happy Harpoon Harry
whalernut posted 08-07-2001 09:53 PM ET (US)
It would seam that that engine setup would also be awsome on the older lighter `16 Hull in which I have a 73` `16 Currituck, and would love a 70h.p. Yam. without the oil-injection. Regards-Jack Graner.
Macman posted 08-08-2001 07:52 AM ET (US)
Jack, just out of curiousity...why would you prefer to mix the gas? Oil injection seems so much easier to deal with. My works perfectly. Am I missing something here?
Whalerdan posted 08-08-2001 09:26 AM ET (US)
750 lbs for 5 people. You guys aren't drinking enough beer.
Clark Roberts posted 08-08-2001 09:43 AM ET (US)
Whalerdan, with the right prop I don't see why a 70hp on a Montauk wouldn't pull wake boards or skis.. However, I'm so old that I never owned a wake board or any of the tubes that I see being towed around. I learned to ski back in about 1950 at age 13 and it was behind a 12' molded plywood Aristocraft with a Merc Hurricane 10hp (actually put out about 16hp) and we would take off on two skis and then drop one to slalom or take off "slack line" standing knee deep as the boat played out the slack (tight line and bingo)! Then I got a 13' mahagony strip Thompson and a Johnson 22hp (opposed twin cyl) and it was the terror of the Fla. panhandle.. we could ski doubles and run in the high 20's.. fellows that was scaulding back then! Then one day a fiberglas (first I ever saw)showed up ,Larson with a Mark 55 Merc (40 hp) and we could go over 30 mph.. Some of you out there may remember those days when we made out own skis and there was no boat traffic etc..etc . Do I get off topic or what!? sorry... Clark... Spruce Creek Navy
mattr posted 08-08-2001 10:01 AM ET (US)
Macman -
You don't happen to keep your boat at Dimillo's, do you? If not, did you pick up some passengers there before your trip yesterday? What do you have for an outboard on your Montauk?
Mattr
Bigshot posted 08-08-2001 10:07 AM ET (US)
That is a nice story Clark. I grew up in the 70-80's and I remember skiing behind rowboats with 20hp's etc. Not hard to do when you weigh 80 lbs:)
whalernut posted 08-08-2001 09:26 PM ET (US)
Macman, I have nothing against oil-injection, except OMC`s separate oil tank-pain in the butt! I am just being old fashioned and trying to keep it simple as I always try to do! I would even like that 70h.p. Yam. without power T/T, but that is impossible anymore, it seems the manufacturers have done away with the manual tilt/trim on the midrange motors. Regards-Jack Graner.
Macman posted 08-10-2001 09:18 AM ET (US)
Matt...That may have been me. My daughter is friends with some of the dock guys at DiMillos...we stopped by to say hello.I trailer the boat...I live about 5 minutes from East End beach, so it is hard to justify the expense of a slip for a 17' boat.
That will have to wait for the 22' Revenge!
Bigshot posted 08-10-2001 10:39 AM ET (US)
If you live on a deep water lake, manual trim is Ok. I live on a river that goes out to the Gulf and I wish I had power tilt on my 15hp(pathetic I know) but when you get stuck in shallows, that oar is not always the right height to make shallow water drive, etc. My father had manual tilt on his 72 100hp Evinrude. How spoiled have we gotten?
mattr posted 08-10-2001 01:40 PM ET (US)
macman -
Yup - Pretty sure that was you, then. Very cool. I work at 100 Commercial street - the big thomas block building, and have an office on the 4th floor that overlooks Dimillos - and the rest of the harbor. I am always scoping out the boat activity - especially whaler sightings - sort of a hobby of mine, since I am boatless at the moment. I had a 23' Oday that I had at a mooring in South Freeport, but the $1,500 a season fee was killing me, so I sold the boat. I agree with you about the trailer deal - the east end is a great place to launch from. Hopefully this fall (or worst case, spring), you'll see me down at the ramp with my own montauk :)
matt
jimmyreeler posted 12-29-2003 12:53 AM ET (US)
i guess my boat is alot smaller than the ones mentioned in the forum. but i was just curious if it is possible to make a 70 hp yamaha go any faster than 45 mph?
Hobie1981 posted 12-31-2003 01:26 PM ET (US)
Jimmy: If you have a pre-smirk Whaler, don't forget how busy that ride is. Are you really sure you want to go that fast? My 1969 Nauset has a 70 HP Yamaha on the transom, and I rarely want to go any faster than 30 mph. The boat will do 38 mph at WOT (5500 rpm). I'll open her up when it's real calm.
Don't forget to be hooked up to your "kill switch".
Only takes 1 time to be throw from your boat, enjoyed that experience last summer.
Hobie

Hop to:

Contact Us | RETURN to ContinuousWave Top Page

Powered by: Ultimate Bulletin Board, Freeware Version 2000
Purchase our Licensed Version- which adds many more features!
© Infopop Corporation (formerly Madrona Park, Inc.), 1998 - 2000.

Author	Topic: Yamaha 70 on a Montauk?
bdb	posted 08-02-2001 06:12 AM ET (US) Anyone running a 70 2 stroke Yamaha on a Montauk or other 17? What can you tell me about performance? (starting, idling, cruise, top end) Thanks, a curious Harpoon Harry
Macman	posted 08-04-2001 11:10 AM ET (US) Harry, I have a 96 70 Yam on my Montauk. I bought the boat late last season. I am very happy with it. I can't give you performance specs,as I am still learning my GPS. Top end (with aluminum prop, don't know the pitch, 17?) is about 31with three passengers (apprx. 500) It trolls at about 1.5 to 2.5, depending on conditions. Starts with one turn, and runs quietly. Very reasonable gas and oil consumption. If I were to repower, I would go with a 90, as I would like the higher top end on occasion. I just got back from a week on the lake, were we cruised about( 4 adults, 3 kids), went tubing, and fished for salmon. It performed flawlessly on all fronts. It pokes around at headway speed especially well. I would be curious to hear from other 70 owners as to top end. I suspect that a new prop might improve the performance. My mechanic told me that the engine was his personal favorite...and that I could plan on having it run for a long time.
Bigshot	posted 08-04-2001 02:55 PM ET (US) You should be in the upper 30's with a 70 with no load. A ss prop usually adds a few mph, no flexing of blades.
bdb	posted 08-05-2001 07:23 AM ET (US) Thanks Macman. For what it's worth I'm currently running an '86 Evinrude 70. Generally, with a couple of people aboard, I top out in the low 30s. Fastest ever was 36 with me, 20 gals of gas, beverages and ice, the dog, and her tennis ball...in a light chop. That's at 5600rpm, 13.25 x 17 stainless from Cabelas. Anybody else have any Yam 70 info? Harry
Clark Roberts	posted 08-05-2001 09:33 AM ET (US) I have had a montauk with yam 70 and four with yam 90's... here's my experience: Yam 70 performance was almost as good as the 90. The 70 was quicker to rev and got great mileage.. toped out at around 37mph... the 90's would run 39-42mph and all with 15" yam stailess prop... non would swing a 17". If I had to run either , I would choose the 70! Just one man's opinion! Clark.. Spruce Creek Navy
Alioop	posted 08-05-2001 01:07 PM ET (US) I have ran a 70hp yamaha's on my boat for 17 years. The performance for me has been very satisfactory,I can get 36 mph with a light load and 34 mph with my usual load(2 people,fishing gear,28 gals.fuel).I puchased a new 86'and ran it for 14 years and found a deal ona left over 98'last year and the 98'is even that much better than the 86'due to the engine computer. I ahd thought of going to a 90 hp but have always had 70 hp on boat since new(1977)and did not want to change the boat.
bdb	posted 08-06-2001 07:39 AM ET (US) Thank you gentlemen. I sure appreciate the opinions and reports.
Mark D	posted 08-06-2001 09:07 AM ET (US) Whats the best pitch prop for a 70 Evinrude on a 17' Montauk?
bdb	posted 08-06-2001 04:23 PM ET (US) Like I said above, I'm running a 17 at 5600rpm. Operating range is 5000-6000, so I'm right in the middle. However, there would appear to be room to go to a 15. In my case the numbers are the same for both aluminum and stainless.
Macman	posted 08-06-2001 09:19 PM ET (US) Clark...just out of curiousity...did you have a Doel fin on your 70 Yam? As I recall you are a fan of this set up, with the motor raised one hole. What think ye?
Clark Roberts	posted 08-07-2001 07:49 AM ET (US) Mack, yes, I had a doel-fin on the 70 Yamaha and can't remember how high I mounted the motor!??? But I know it wasn't in the lowest position. Clark
Whalerdan	posted 08-07-2001 08:00 AM ET (US) Clark, do you think this setup would put a wakeboarder up? I find a wakeboard to be much easyer to pull up than a skier.
Whalerdan	posted 08-07-2001 09:06 AM ET (US) Does anyone know what the real horsepower output is for the yam 70 and 90?
Bigshot	posted 08-07-2001 11:02 AM ET (US) it is 70 and 90 respectively. People mistake HP for torque. The 90 Yamaha is 90hp but lacking in cubes compared to a v-4 it has less grunt. Hp dictates what it will do and torque says how fast you will do it. I am completely happy with my 90 Yamaha and I had a 115 Johnson on a montauk. With 4 adults and gear, etc, she pulls right out of the hole without tucking in the engine. I am the happiest with the weight and gas savings. A 70hp would be fine but for the few hundred I would hate to regret it.
Macman	posted 08-07-2001 06:47 PM ET (US) An update.....went for a 50 mile cruise today in all sorts of conditions. Chop, calm, 3 ft groundswell, you name it. With 5 people (apprx. 750 lbs) plus gas ( 19 gals), at 4100, the gps was reading 21-23 knots. I will not know my gas consumption until I fill the tank tomorrow. I suspect about 10 gals.was used. A great day on Casco Bay!
bdb	posted 08-07-2001 09:46 PM ET (US) Thanks guys... The feedback is fantastic, and just what I needed to hear/read. It all bears out my feelings that the yam 70 would be a great general purpose Montauk motor. Happy Harpoon Harry
bdb	posted 08-07-2001 09:46 PM ET (US) Thanks guys... The feedback is fantastic, and just what I needed to hear/read. It all bears out my feelings that the yam 70 would be a great general purpose Montauk motor. Happy Harpoon Harry
whalernut	posted 08-07-2001 09:53 PM ET (US) It would seam that that engine setup would also be awsome on the older lighter `16 Hull in which I have a 73` `16 Currituck, and would love a 70h.p. Yam. without the oil-injection. Regards-Jack Graner.
Macman	posted 08-08-2001 07:52 AM ET (US) Jack, just out of curiousity...why would you prefer to mix the gas? Oil injection seems so much easier to deal with. My works perfectly. Am I missing something here?
Whalerdan	posted 08-08-2001 09:26 AM ET (US) 750 lbs for 5 people. You guys aren't drinking enough beer.
Clark Roberts	posted 08-08-2001 09:43 AM ET (US) Whalerdan, with the right prop I don't see why a 70hp on a Montauk wouldn't pull wake boards or skis.. However, I'm so old that I never owned a wake board or any of the tubes that I see being towed around. I learned to ski back in about 1950 at age 13 and it was behind a 12' molded plywood Aristocraft with a Merc Hurricane 10hp (actually put out about 16hp) and we would take off on two skis and then drop one to slalom or take off "slack line" standing knee deep as the boat played out the slack (tight line and bingo)! Then I got a 13' mahagony strip Thompson and a Johnson 22hp (opposed twin cyl) and it was the terror of the Fla. panhandle.. we could ski doubles and run in the high 20's.. fellows that was scaulding back then! Then one day a fiberglas (first I ever saw)showed up ,Larson with a Mark 55 Merc (40 hp) and we could go over 30 mph.. Some of you out there may remember those days when we made out own skis and there was no boat traffic etc..etc . Do I get off topic or what!? sorry... Clark... Spruce Creek Navy
mattr	posted 08-08-2001 10:01 AM ET (US) Macman - You don't happen to keep your boat at Dimillo's, do you? If not, did you pick up some passengers there before your trip yesterday? What do you have for an outboard on your Montauk? Mattr
Bigshot	posted 08-08-2001 10:07 AM ET (US) That is a nice story Clark. I grew up in the 70-80's and I remember skiing behind rowboats with 20hp's etc. Not hard to do when you weigh 80 lbs:)
whalernut	posted 08-08-2001 09:26 PM ET (US) Macman, I have nothing against oil-injection, except OMC`s separate oil tank-pain in the butt! I am just being old fashioned and trying to keep it simple as I always try to do! I would even like that 70h.p. Yam. without power T/T, but that is impossible anymore, it seems the manufacturers have done away with the manual tilt/trim on the midrange motors. Regards-Jack Graner.
Macman	posted 08-10-2001 09:18 AM ET (US) Matt...That may have been me. My daughter is friends with some of the dock guys at DiMillos...we stopped by to say hello.I trailer the boat...I live about 5 minutes from East End beach, so it is hard to justify the expense of a slip for a 17' boat. That will have to wait for the 22' Revenge!
Bigshot	posted 08-10-2001 10:39 AM ET (US) If you live on a deep water lake, manual trim is Ok. I live on a river that goes out to the Gulf and I wish I had power tilt on my 15hp(pathetic I know) but when you get stuck in shallows, that oar is not always the right height to make shallow water drive, etc. My father had manual tilt on his 72 100hp Evinrude. How spoiled have we gotten?
mattr	posted 08-10-2001 01:40 PM ET (US) macman - Yup - Pretty sure that was you, then. Very cool. I work at 100 Commercial street - the big thomas block building, and have an office on the 4th floor that overlooks Dimillos - and the rest of the harbor. I am always scoping out the boat activity - especially whaler sightings - sort of a hobby of mine, since I am boatless at the moment. I had a 23' Oday that I had at a mooring in South Freeport, but the $1,500 a season fee was killing me, so I sold the boat. I agree with you about the trailer deal - the east end is a great place to launch from. Hopefully this fall (or worst case, spring), you'll see me down at the ramp with my own montauk :) matt
jimmyreeler	posted 12-29-2003 12:53 AM ET (US) i guess my boat is alot smaller than the ones mentioned in the forum. but i was just curious if it is possible to make a 70 hp yamaha go any faster than 45 mph?
Hobie1981	posted 12-31-2003 01:26 PM ET (US) Jimmy: If you have a pre-smirk Whaler, don't forget how busy that ride is. Are you really sure you want to go that fast? My 1969 Nauset has a 70 HP Yamaha on the transom, and I rarely want to go any faster than 30 mph. The boat will do 38 mph at WOT (5500 rpm). I'll open her up when it's real calm. Don't forget to be hooked up to your "kill switch". Only takes 1 time to be throw from your boat, enjoyed that experience last summer. Hobie