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

JoeCool · October 6

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?

gandrfab · October 6

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.

CaptJ · October 7

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.

surfman · October 7

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.

polliwog · October 7

You could always look at the Evinrude 2 stroke 115HP , Check out the weight difference .

Flec · October 7

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 Monoxide · October 7

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?

JoeCool · October 7

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

surfman · October 8

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.

Flec · October 8

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.

JoeCool · October 8

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!

JoeCool · October 8

Tarpon Monoxide - I stated I had a 25" transom, however your question made me measured it and it is 20", not 25" as stated.

snookaffinity · October 8

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.

tarpon41 · October 8

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

surfman · October 9

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.

JoeCool · October 9

Tarpon41- How would I check the transom core?

Tarpon Monoxide · October 9

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.

Soda Popinski · October 9

So grab the 140 zuke, and some 115 decals.......

tarpon41 · October 9

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

surfman · October 9

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.

JoeCool · October 9

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.

surfman · October 10

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.

big_t · October 24

I had a 140 suzi on a keywest stealth. The motor is not 140 hp. It is a great motor, but it barely pulls it's weight. Runs quiet, smooth and is reliable. What it isn't is 140 hp, Get the evinrude, you will be happier if speed is what you seek.

lemaymiami · October 25

I have to disagree with anyone recommending a raised transom for that older Mako... That hull was designed with a 20" transom from the beginning... and if you raise the transom to accommodate a motor with a 25" shaft -you're also going to be installing a heavier 25" motor.... That rig does okay with a 90 - runs very well with a 115, and will scream with a 135 or 140 hp motor... Take your choice. The original motors from the classic era were all very lightweight 2 strokes in the V4 category, mostly... All of them from OMC (BRP now...)- the 90, 115, 135 weighed the same 305lbs... The closest in current motors to that 305 pounds is the currently available Evinrude E-Tec 90 at 320 pounds. I know since I'm on my fourth one (on a 31 year old Maverick that I work out of....). As you go up in horsepower these days - you go up in weight - no getting around it... The plus side is that today's motors are much much more clean burning (the E-Tec, the only two stroke still being made... is the champ for emissions - no four stroke can touch it...), every new motor, 2 stroke or 4 stroke is very much more fuel efficient than motors from thirty years ago...

Get all the brochures then check out comparable weights as one way of making a selection.... Unless you have a brand new fuel tank - I'd be very leery of any four stroke unless you've had the tank completely emptied, steam cleaned, etc. Today's fuels are nothing like the gasolines of thirty years ago - that's why anyone with a four stroke motor goes looking for fuel that doesn't have any ethanol blended in... I've been running nothing but ethanol laced fuel for every E-Tec I've ever had (since 2005 in hard commercial service) and my motors never have a fuel problem at all...

By the way with an older boat - along with re-habbing that fuel tank - make a point of replacing every bit of your fuel lines with USCG rated ethanol resistant lines... Avoid any big box store's fuel line - go directly to a quality marine hardware store for the line - it will have the USCG rating printed right on the line - continuously....

By the way, if you haven't guessed by now I'm lucky enough to be on BRP's guide program and was on OMC's guide program before that.... I might be a bit biased about Evinrude or Johnson engines since that's all I've ever run (since 1974, and I didn't get on anyone's guide program until after 1996...).

The current much heavier motors (particularly four strokes) work just fine with new rigs since the hull was designed from the beginning to carry and run with the current motors.. Older hulls like mine - and that Mako were designed to run, float, and ride with much lighter motors... In the under 20' hulls it will make a difference in whether the hull floats level at rest (only important if you want to ease it into the shallowest of waters) or how it drains if self bailing at rest (might be important if you keep your rig in the water...). In bigger boats (particularly hulls with twin or triple motors that were originally designed for relatively lightweight motors) - those nice new four strokes might cause you some serious problems, since those hulls were never designed to carry that much weight in the stern...

Hope this helps... aren't boats fun?

Tarpon Monoxide · October 27

"That hull was designed with a 20" transom from the beginning."

When the classic mako 17 was designed there were only 20 inch shaft outboard motors and 25 inch shaft motors did not come out until years later. So when the 17 mako was designed there was no such thing as a 25 inch outboard nor 25 inch transom. So the mako 17 design was stuck with the low 20 inch transom.

I would have to disagree with not raising the transom up to 25 inches. The classic mako 17 was designed well before 25 inch motors were built that needed 25 inch transoms so the old classic mako 17 continued to be made with the low 20 inch transom well after 25 inch shaft motors came out.

I have seen 20 years of what raising a classic mako 17 transom up from 20 inches to 25 inches has done for the safety of the boat and for the less internal corrosion of the motor. I have seen only advantages and I have seen no disadvantages. Raising the transom to 25 inches only makes the boat better and safer and that has been borne out with seeing the difference in the last 20 years.

If someone is going to put a new motor on a 20 inch transom when they could raise that transom up and make the boat safer is not protecting their investment and their safety as best they can. And when you get into rough water and you have slash over the transom you will regret not having the extra 5 inches.

lemaymiami · October 27

I can readily see how anyone operating in the ocean would want a 25" transom... The vast majority of the 17' hulls that I'm familiar with are inshore operators.... Yes, you can always go to a 25" transom - and that heavier 25" shafted motor - you'll also get more weight at the stern with it... That's why I wrote what I did... If you're familiar with the Mako line you also know that it's been around for at least forty years - and was never meant to have heavier motors at the stern. Yes, you can do it and live with it - but for inshore use where getting up into shallow areas might be important - it's definitely something to consider...

The rig I've worked out of for the past 24 years is something similar, an old Maverick hull that's just two inches shy of 17 feet long. I got it in 1988, long before I took up guiding - and had the great fun of rigging it out myself from scratch.... Can't tell you how many motors that hull has seen over the years. My average day on the water works out to be a round trip of about 70 miles into the backcountry of the Everglades... so that's where I'm coming from.... and yes - it's got that terrible 20" transom....

Hope this helps... aren't boats fun?

CaptJ · October 28

I repowered a 1986 20' Mako with a Yam 150 4 stroke and although the transom was already @ 25" the motor is considerably heavier than the 200 v6 that was on there. By moving the batteries (2 x #29's) to the console everything balanced out and the boat sits exactly the same as before. I fish the backcountry with this boat and can run in extremely thin water with no problems. I think every solution has positives and negatives which can be solved by careful planning. Nice to have the 25" transom when I go offshore and anchor down.

Tarpon Monoxide · October 29

"it's got that terrible 20" transom.... "

I don't see any posts that say a 20" transom is terrible. A 20" transom is the right height for low gunnel flats boats, but the classic 17 mako is not in that category.

I never said that all boats with 20" transoms would benefit from raising the transom to 25" because that is not the case. Only certain boats with 20" transoms benefit from a 25" transom and your boat is not one of them.

"Yes, you can always go to a 25" transom - and that heavier 25" shafted motor - you'll also get more weight at the stern with it... That's why I wrote what I did... If you're familiar with the Mako line you also know that it's been around for at least forty years - and was never meant to have heavier motors at the stern."

As I said the Mako 17 was forced to be designed with a 20" transom because at that time there was not such thing as a 25 inch shaft outboard.

A good friend got a Mako before 25 inch shaft motors and put a 310 pound merc inline 6 on it with a 20 inch shaft to go with the 20 inch transom.

Even with the lighter 20 inch shaft 2 stroke 300 pound 115 HP motor the top of the transom sat low to the water.

When that motor died he got a new 4 cylinder 2 stroke merc that weighted more at 350 pounds. Since he knew that the new motor weighed 40-50 more pounds and the transom sat low to the water with the old 300 pound merc he took the boat and had the transom raised to 25" for the new 4 cylinder 2 stroke (about 1998). He has been nothing but delighted with the results.

"Yes, you can always go to a 25" transom - and that heavier 25" shafted motor - you'll also get more weight at the stern with it... That's why I wrote what I did.."

The difference between the 20" and 25" shaft is small.

Etec 90 20" shaft = 320 pounds

Etec 90 25" shaft = 335 pounds

Only 15 pounds extra for the 25" shaft in the 90 Hp version.

Etec 2 stroke 115 25" shaft = 390 pounds.

Mercury 4 stroke 115 25" shaft = 383 pounds

Suzuki 4 stroke 115 25" shaft = 412 pounds

Yamaha 4 stroke 115 25" shaft = 386 pounds

These 115 HP 25" shafted motors are about 25 pounds more than the 20" shaft versions.

Notice the 2 stroke Etec 115 weights more than the 4 stroke Mercury 115 and Yamaha 115.

"If you're familiar with the Mako line you also know that it's been around for at least forty years - and was never meant to have heavier motors at the stern."

Correct the 17 classic mako was never meant to have heavier motors on it. But since heavier motors have come out then best to alter the original forced design of the classic 17 mako boat with a higher 25" transom because those heavier motors are going to pull down the transom even more so those extra 5 inches are well worth the investment.

mlange · November 2

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 weigh 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?

The 115 and 140 are practically the same. save the $$. had a customer insist on upgrading the engine on a new boat perigged with the 115. I had the rigger test the boat before and after the swap, the difference was not noticeable.

Tarpon Monoxide · November 3

The 115 4 stroke Suzuki has the same exact bore and stroke as the 140 Suzuki. The Suz 140 is just tuned up a little to get more horsepower out of the same powerhead that the 115 Hp has. It does not cost Suzuki a penny more to make the 140 over the 115 but they charge more for the 140.

It is not worth the extra money for a 140 over a 115 because the 140 will get you less than 5 mph at top speed more like 3 mph..

Fact is the detuned 115 on the same boat will beat the 140 off the line because of the way its is tuned, The 140 will have a little better top end but not enough to justify the price difference.

I see you are leaning to the Pro XS Merc 4 stroke 115. That is a good choice, if it was me I would get the regular merc 115 4 stroke and save some money

JoeCool · November 8

just to wrap up the thread, I wound up repowering with a 2013 4-Stroke 115. It is a freshwater use motor with only 63 hours and in like new condition. Problem solved! I decided that mounting a 140 was not worth the insurance risk.

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

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