17ft Mako CC 70HP?!

[Chrisravosa36]

Hi, just bought my mako 17ft boat today, its a CC and it rated at 135hp max. No motor on it, was looking into a few. Its going to be an ocean boat, so it doesn't need to go to fast. Hull weighs 1200lbs, I probably have 200lbs MAX accessories and gear (Batteries, electronics rods ect.) I know a 70hp will work, and it will be great on gas but is it too small?! Its a 1987 70hp Johnson. I was looking at the v4's aswell, but id like something that wont drink as much. What should I expect with a 70? Im not in anyway looking for the fastest boat on the water, just something that will be responsive and keep me safe at sea.

 

[hardwater fisherman]

That will be only around half max hp. Maybe you should be looking for a 90hp or more.

 

[Chrisravosa36]

That will be only around half max hp. Maybe you should be looking for a 90hp or more.

Alright. I was thinkking that anyways, but ive seen some really good deals on these 70hps.would an 85hp do it?

 

[Fed]

A 70HP should get you ~30MPH at WOT and a 90HP should get you ~40MPH, I have tried both on my very similar boat.

 

[jbcurt00]

Better then a 70, not as good as a 90, but not by much.

70% max HP is a good general rule of thumb. As w most general rules, there will be exceptions. Wont know if an 85hp will or wont be sufficient until it is or isnt. Same w a 90, though......

 

[hardwater fisherman]

^^^ There you go someone with some more knowledge then me for your type of boat. As long as you can plane without too much trouble and you are happy with it then go for it.Yes and 70 percent is around 95hp.

 

[jbcurt00]

^^^ There you go someone with some more knowledge then me for your type of boat. As long as you can plane without too much trouble and you are happy with it then go for it.

He's referring to the post above mine by Fed.

Although 40mph sounds high to me w a 90 on a boat rated for a 135. But I dont own anything remotely similar to a 17ft Mako.

 

[hardwater fisherman]

Yes you got in between my ^^^. I would think that 90hp would be the minimum for a boat rated at135. Also I dont own anything like that. So not sure.

 

[Fed]

I take it back, mine is a bit lighter than yours.

The 90 HP has seen 42 MPH with a tail wind, the max 175 HP would be downright scary.

 

[Chrisravosa36]

YEAH.....Its not to heavy of a boat, I think that a 85 or 90hp is what im going to be looking for. I think 135hp would be to much, but back in the day it was the same V4 Design, so it was not alot of added weight on the back, just more power. Now a 135hp would let water in the self bailing hull.

 

[Fed]

It sounds like a V4 is the way to go, be aware they changes the HP rating in the mid 80's from engine to prop so an early 80's HP is less than a late 80's one.
I think the 85 HP was only engine rated, not 100% sure though.

 

[oldboat1]

Some experience with a center console Mako (17'), if that helps -- friend's boat (mid-70s rig). It was pretty underpowered with an 85. Stable but heavy hull (good to be sure you don't have waterlogged foam under the floor, btw -- don't need the extra weight). We ran on the Chesapeake and the boat handled the chop pretty well, but more power would have been better for outrunning storms.

 

[Chrisravosa36]

Some experience with a center console Mako (17'), if that helps -- friend's boat (mid-70s rig). It was pretty underpowered with an 85. Stable but heavy hull (good to be sure you don't have waterlogged foam under the floor, btw -- don't need the extra weight). We ran on the Chesapeake and the boat handled the chop pretty well, but more power would have been better for outrunning storms.

Ok I think im going to be looking at a 100 - 120hp then. Im really only interested in the OMC motors, they are simple and these v4 are bulletproof. Im waiting on a response from the P.O whether the foam was good or not, what is the best way to check it? Drill holes im guessing.

*Good thing is that the deck does not look like the original color, which leads me to believe it was redone.

 

[Chrisravosa36]

so looking back to 1976 the 135hp weighed in at 290lbs, nowadays (1990's) a 115 is 335lbs, thats 45lbs more..... wont this be a little too much weight on a self bailing deck?!

What am I looking at for a cruise speed on a 1200lb Mako 17ft hulll, about 700lbs of people and all gear. and 335lb 115hp motor.

Probally a late 80's or early nities. I know its about 12GPH WOT. but im looking for a good cruise speed, like 20-25mph. I know its a hard question with no test runs, just Id want to know the ball park. Also how about WOT?! 40mph?!

 

[Dixiedawg]

Hi Chis, I own a 78' McKee Craft Southporter, which is a 17'4" dual console, hull weighing in at 1400 lbs. The boat had a 79' 100hp evinrude when I got it, and last year I replaced it with a 77' 115hp evinrude. The 100hp was just adequate, but I definitely wouldn't have wanted to go smaller. The 115hp is just about right. The boat topped out at around 35 mph with the 100hp per gps, and I would guess about 40mph with the 115hp (gps broke). I don't feel like my gas usage went up at all with the 115 (we usually cruise at around 3600 rpm's) so I don't think more hp always necessarily means more gas consumption, if the boat is under-powered with the smaller motor! I know my hull is a little heavier than yours, so take this info for what it's worth!

 

[oldboat1]

(on checking for water logging)

As you mention, drill holes in the transom above the bottom skin, somewhere around the keel, probably a little below the brass drain and right and left of it -- hull tilted back on the trailer (repair is with thickened epoxy or some 5200) -- 1/8" bit to maybe 1/4". Move up the transom a little too to see if you have some punky wood core -- assuming the Mako had a wood core. Use your nose too. If you get some drainage that smells like swamp water, it's been in there for a while and you have some rot. (Want to replace the transom core if necessary before repowering. You may have done it before -- DIY job, but some work involved.) If serious water intrusion, you can go in through the floor and open up an area over the keel, on towards the stern. (Makes for a good storage compartment with some carpentry after pumping/draining.) All depends on what you find. They all let water down from the top, so it's a decision.

New floor can be good news -- or a patch. Question the PO about what was done (and why).

 

[Chrisravosa36]

Hi Chis, I own a 78' McKee Craft Southporter, which is a 17'4" dual console, hull weighing in at 1400 lbs. The boat had a 79' 100hp evinrude when I got it, and last year I replaced it with a 77' 115hp evinrude. The 100hp was just adequate, but I definitely wouldn't have wanted to go smaller. The 115hp is just about right. The boat topped out at around 35 mph with the 100hp per gps, and I would guess about 40mph with the 115hp (gps broke). I don't feel like my gas usage went up at all with the 115 (we usually cruise at around 3600 rpm's) so I don't think more hp always necessarily means more gas consumption, if the boat is under-powered with the smaller motor! I know my hull is a little heavier than yours, so take this info for what it's worth!

Thanks, it helps, im going with a 110hp or above.

 

[joezek]

I have a 73 Angler. I had a 140 Looper on it which got me about 52 per the GPS @ WFO. recently it died, blew the lower main bearings.

I just temporarily stuck on a 90 and it's nice. It's super quiet, jumps on plain and tops out at 37 mph. Not bad since the boat is a little heavy. It's heavy because I know it's holding water from a few ramp mishaps, and I have a crazy stereo system with 3 group 31 batteries, also a T top and a few coolers, custom seats etc