140HP on Mako 17 Classic (135HP Max Rated (j

JoeCoolJoeCool Posts: 90 Greenhorn
I own a 1985 Mako 17 Classic with a 1998 90HP Mariner. I want to re-power early next year. The existing 90HP runs great, but seems marginal in power. The boat is heavier than most modern boats and I have it loaded pretty good (MK Ulterra with 2 Batteries in bow, 2 crank batteries in the console and other gear).
i would love for the re-power to provide high 30's in top MPH and to be able to cruise at 30 MPH.

I am running a 4 blade 15P prop getting 29 MPH @ 5350 RPM. Can cruise @ 24 MPH @ 4800 RPM. My existing 115 Mariner weighs only 305 Lbs. wanting to stay as light as possible, I am considering a 115 Merc 4-Stroke (363 lbs) or a Suzuki DF115 (413 lbs). 

My question is - Should I consider a 140 Suzuki (same weight as 115 Suzuki). I would like the extra power and am not concerned about fuel economy as I don't make long runs. Problem is, the Mako is rated for 135 max HP. Florida Statutes says you cannot over power, but states no penalty for doing so. I would only be 4% over powered. Any experience or thoughts about which way I should go?

Replies

  • gandrfabgandrfab Posts: 20,729 AG
    You are fine until you have accident then it can be used against you in the court of law. 
    Other than that go for it. 

    You may have problems insuring it when powered above recommended max power. 
    :BUNNY gestapo

  • CaptJCaptJ Posts: 872 Officer
    I repowered a 1986 20' Mako CC with a new Yamaha 150 and top end is about 43 mph fully loaded (60 gal gas, etc). Boat runs really well at about 26 mph with great fuel economy. I'm very happy with the performance.
  • surfmansurfman WC FLPosts: 5,981 Admiral
    As long as the weight is the same you are good as far as I am concerned, the added weight of a bigger motor can be a problem due to the fact that the transom will sit lower in the water, if it is not a factor then go for it. My buddies old 19' classic Mako has a very low transom, I am thinking your 17 is probably about the same.
    Tight Lines, Steve
    My posts are my opinion only.

    Be thankful we're not getting all the government we're paying for.  Will Rogers
  • polliwogpolliwog Posts: 259 Deckhand
    You could always look at the Evinrude 2 stroke 115HP , Check out the weight difference .
  • FlecFlec Posts: 583 Officer

    Sucks that todays outboards are so much heavier than they were 20/30 years ago. Even 2 strokes are much heavier.

    I repowered my 20' GradyWhite in 2004 with a Yamaha 150 fourstroke from a 1993 Johnson V6 175hp and added 110

    pounds to the transom. Yes,,I did gain 40% better fuel efficiency though.


  • Tarpon MonoxideTarpon Monoxide Posts: 552 Officer
    JoeCool said:
    I own a 1985 Mako 17 Classic with a 1998 90HP Mariner. I want to re-power early next year. The existing 90HP runs great, but seems marginal in power. The boat is heavier than most modern boats and I have it loaded pretty good (MK Ulterra with 2 Batteries in bow, 2 crank batteries in the console and other gear).
    i would love for the re-power to provide high 30's in top MPH and to be able to cruise at 30 MPH.

    I am running a 4 blade 15P prop getting 29 MPH @ 5350 RPM. Can cruise @ 24 MPH @ 4800 RPM. My existing 115 Mariner weighs only 305 Lbs. wanting to stay as light as possible, I am considering a 115 Merc 4-Stroke (363 lbs) or a Suzuki DF115 (413 lbs). 

    My question is - Should I consider a 140 Suzuki (same weight as 115 Suzuki). I would like the extra power and am not concerned about fuel economy as I don't make long runs. Problem is, the Mako is rated for 135 max HP. Florida Statutes says you cannot over power, but states no penalty for doing so. I would only be 4% over powered. Any experience or thoughts about which way I should go?
      Do you have a 20 inch transom?
    Colon Kapermick Nike's Stephin Fetchit

    America, the land of the "regressives" proposed free health care for illegal aliens paid for by legal tax paying Americans who have to pay exorbitant rates for their own health insurance.
  • JoeCoolJoeCool Posts: 90 Greenhorn
    Have a 25" transom. I do have scuppers over a small 3" deep well. Since I need to repower, any new motor I can buy will be heavier than my existing 90 Mariner at 305 lbs. The Mercury is  the lightest at 363#. The etecs are heavier than the Merc. I am leaning toward the Mercury 115 Pro XS (about $9k plus rigging labor). I have heard that a harness adapter is available so I can reuse my existing controls. 

    My main question is... Should I consider a 140 Suzuki which would be 5HP over my max HP rating. The 140 weighs the same as their 115 (413#) and cost the same as the 115 Pro XS Merc. The Suzuki has a 6 year warranty and mercs and yammies only 3 years.

    what I dont want is an issue with FWC or Marine Patrol
  • surfmansurfman WC FLPosts: 5,981 Admiral
    edited October 8 #9
    I don't think 5 hp is going to make any difference, the weight will be the biggest factor.

    You could calculate the difference and then add a couple of sand bags to the back of the boat and see what happens, if you can live with it sitting lower in the water then that is what you will get.
    Tight Lines, Steve
    My posts are my opinion only.

    Be thankful we're not getting all the government we're paying for.  Will Rogers
  • FlecFlec Posts: 583 Officer
    The Yamaha 115 is 386lbs and should give you an easy 30MPH cruise with a top end around 43MPH. Try to find a performance report online for a similar size boat with the 115.
  • JoeCoolJoeCool Posts: 90 Greenhorn
    Surfman  - great idea. 2 5 gallon buckets of water would be about right.

    Flec - I just looked at the Yamaha performance site. I looked at boats of similar design, but about 1600# (mine is 1400#) to compensate for my heavy TM and dual batteries in the bow compartment. Closest match was a Key West 18-8.  I have decided that  115 is all I will need. I am leaning toward the Mercury 115 Pro XS. THANKS!


  • JoeCoolJoeCool Posts: 90 Greenhorn
    Tarpon Monoxide - I stated I had a 25" transom, however your question made me measured it and it is 20", not 25" as stated.
  • snookaffinitysnookaffinity Naples, FLPosts: 1,135 Officer
    JoeCool said:
    Surfman  - great idea. 2 5 gallon buckets of water would be about right.

    Flec - I just looked at the Yamaha performance site. I looked at boats of similar design, but about 1600# (mine is 1400#) to compensate for my heavy TM and dual batteries in the bow compartment. Closest match was a Key West 18-8.  I have decided that  115 is all I will need. I am leaning toward the Mercury 115 Pro XS. THANKS!

    That would be my choice.

    "It is better to keep your mouth closed and let people think you are a fool than to open it and remove all doubt." - Mark Twain
  • tarpon41tarpon41 Posts: 218 Deckhand
    JC...Long time ago '83 I had a '82 Angler with 20" I used a  1982 140 OMC...but in those days HP was measured at the crank not the prop shaft like today...that 115 should make it fly even though you're haulin a barge load a coal down the Mississippi ...my Angler with the 140 under light load low fuel and me, would chine walk trimmed out running down the inside from Naples to Goodland...I had it in service until '90.  I had some erosion/rot in the plywood transom core...I would check your transom core before hanging the new Merc on her stern     
  • surfmansurfman WC FLPosts: 5,981 Admiral
    edited October 9 #15
    I think the 115 would be plenty, my buddy had a 115 on his '19 and it was fine, he did upgrade later to the 140 though. And we are talking 1980's Evinrudes too.

    The weight needs to be off the back of the transom, like the motor though. a sand bag or two or three on top of the motor would bee more accurate.
    Tight Lines, Steve
    My posts are my opinion only.

    Be thankful we're not getting all the government we're paying for.  Will Rogers
  • JoeCoolJoeCool Posts: 90 Greenhorn
    Tarpon41- How would I check the transom core?
  • Tarpon MonoxideTarpon Monoxide Posts: 552 Officer
    edited October 9 #17
    JoeCool said:
    Tarpon Monoxide - I stated I had a 25" transom, however your question made me measured it and it is 20", not 25" as stated.
    I thought it was a 20 inch transom. I did not think that Mako in the 80's put 25 inch transoms on their 17 Makos.

    I had an Aquasport with a 20 inch transom. When I went to repower I took the boat and had the transom raised to 25 inches and got a 25 inch shaft motor. That extra 5 inches on the transom made the boat much safer and also raised the motor higher off the water which allows less water intrusion.

    Once I did that a friend of mine that has a classic old 17 Mako that had a 20 inch transom saw how much safer and better it made my Aquasport. He had to repower so he took his 17 Mako and had the 20 inch transom raised to 25 inches and got a 25 inch shaft motor. Because of the original 20 inch transom the motor sat low to the water and in some situations the water would splash over the low transom.

    My friend that has the Mako with the raised transom to 25 inches was delighted with the results.

    If you are going to spend for a new 4 stroke it would be wise to have the transom raised to 25 inches and get a 25 inch shaft motor. You will benefit by having more safety and a motor raised up 5 inches more.

    Also since you are adding more weight to the transom that is just another reason to raise the transom from 20 to 25 inches.

    I have another friend that has an 18 seacraft with 20 inch transom. Because of the deep v the transom was only a few inches out of the water. Not good, so when it was time to repower he also took his boat in a had his 20 inch transom raised to 25 inches and then got a 25 inch new motor. He is happy he did it.

    If it was me I would find a quality fiberglass shop and have them raise up your transom to 25 inches and I guarantee you will be glad you did. At that time they can check your transom for wood rot.






    Colon Kapermick Nike's Stephin Fetchit

    America, the land of the "regressives" proposed free health care for illegal aliens paid for by legal tax paying Americans who have to pay exorbitant rates for their own health insurance.
  • Soda PopinskiSoda Popinski GrovelandPosts: 11,035 AG
    So grab the 140 zuke, and some 115 decals.......
    People use statistics the way a drunk uses a street light, for support rather than illumination.
  • tarpon41tarpon41 Posts: 218 Deckhand
    I agree raise transom 25 "  ...or lighten stern... no coolers no bait wells used if fishing outside  and 115 Merc and stay with 20 in...I checked my transom by taking a 1/4 in long drill and drilled down checked chips for moisture and condition of wood...this is what I did and I make no warranties...pulled it out...drilled 6  1/2 in holes into plywood core evenly spaced across transom starting on center... core was good about 8-10 in either side of engine center line...made sure ...then filled 1/2in holes with acetone waited until evaporated...then filled holes with that real thin  epoxy  recall it was called "Git Rot" or something like that...kept topping it off....kept boat for another 18 months ...engine didn't fall off...but my recollection was at anchor with two of us casting or bait fishing in the stern the there was only about 1 or 2 in of free-board at the transom ...I would raise transom to 25"  if you are going to keep the boat.  The best inside and inshore boat  I had in the 90ies for SW FLA Goodland area...was an old 13 Whaler, I raised the transom to 20 from 15 but a 40hp Yamaha w/o trim and tilt tuned the 40 to 50 specs...with 400 lbs, two of us, at the stern fighting live baited Snook in those halcyon days Caxambas pass or Cape Romano...that13 Whaler had 3-4 in of free board at the transom     
  • surfmansurfman WC FLPosts: 5,981 Admiral
    Yea, we went diving in the Gulf back then in that 19 Mako and it wasn't usual for the back of the boat to be full of water. It really wasn't made for that kind of thing. We were young and dumb.
    Tight Lines, Steve
    My posts are my opinion only.

    Be thankful we're not getting all the government we're paying for.  Will Rogers
  • JoeCoolJoeCool Posts: 90 Greenhorn
    Thanks everyone for REALLY GOOD advice! Any idea what it would cost to have the transom raised and who to have do the work. If it gets really expensive, I may consider selling the entire rig and buy a new or "newer" one. My existing rig runs great and we do not fish past the sea buoy. I am about to retire, plan to fish a lot more and just want a 4-stroke as they seem quieter and more dependable than my 20 year old 2-stroke.
  • surfmansurfman WC FLPosts: 5,981 Admiral
    There's no telling, when the get into the work they may find out that the transom needs to be rebuilt, then it would be more money of course, The first thing you need to find out is what kind of condition it is in to begin with. Even a repower constitutes inspecting the condition of the transom on an old boat with wood core.
    Tight Lines, Steve
    My posts are my opinion only.

    Be thankful we're not getting all the government we're paying for.  Will Rogers
Sign In or Register to comment.