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Author Topic:   repowering a 17ft with 50hp.......?
stinkyB posted 07-11-2003 01:09 PM ET (US)   Profile for stinkyB   Send Email to stinkyB  
I want to repower my old 17ft whaler. It currently has a 75 hp , unfortunately $$ won't let me put that many ponies on the back, and was thinking of getting a 50hp due to economics (less weight could be a +).

I know she won't be fast, but I'm going fishing, not racing ;) , but Will she be way underpowered?

cdnturbo posted 07-11-2003 01:13 PM ET (US)     Profile for cdnturbo  Send Email to cdnturbo     
Years ago when I worked at one of the local yacht clubs they had a 17' with a 50 that I would operate , it went just fine.
Bigshot posted 07-11-2003 01:19 PM ET (US)     Profile for Bigshot  Send Email to Bigshot     
Many people here have 50's on their 17's and they all report low 30's as top speed. If load is light then a 50 will do fine. I have a 70 which is plenty. Have you considered a slightly used larger engine? Resale I think will suffer with a 50 so you might save now but pay later.
stinkyB posted 07-11-2003 01:38 PM ET (US)     Profile for stinkyB  Send Email to stinkyB     

I've thought about that, but like the "security" of having a warranty on a new engine, but to be honest I haven't researched it much.

Going fishing, my load isn't always very light (gear, livewell, ice, etc) so that's why I was wondering.

The boat is old ('65) and not in great shape, so also though a smaller/lighter engine would be easier on the transom. I guess a late model used engine could be an option, but I don't have a whole lot of knowledge / experience where to start / what to expect.


Jarhead posted 07-11-2003 04:52 PM ET (US)     Profile for Jarhead  Send Email to Jarhead     
Have you given any thought to having your 70hp rebuilt?

If it isn't too far gone it might be worth doing....

JBCornwell posted 07-11-2003 05:58 PM ET (US)     Profile for JBCornwell  Send Email to JBCornwell     
Hi, Stinky.

Tell us about your 75hp.

What model and brand? Why do you feel it needs replacing?

If it is an OMC triple looper you already have one of the best engines ever for a 16'7" hull. It probably can be made well and reliable for a lot less cost than it can be replaced for.

Red sky at night. . .

whalernut posted 07-11-2003 08:08 PM ET (US)     Profile for whalernut  Send Email to whalernut     
If money is an issue as you say it is, I imagine the 50/60 h.p. 4-strokes are out? If not, I would consider the Evinrude/suzuki 50 4-stroker or the Mercury 50/60 4-stroker, can`t go wrong with either, but I do know, the Rude/Zuki is Fuel Injected, I like that idea :) Are the Mercs Fuel Injected? Jack.
Dick posted 07-11-2003 09:59 PM ET (US)     Profile for Dick  Send Email to Dick     

I have a Merc 50 4 stk on my 99 Montauk. With 25+ gallons of fuel, two adults, a fat dog and several pounds of stuff that could have been left at home,on the GPS I top out at 33 mph @ 5800 rpm.


Whalerdan posted 07-13-2003 05:39 AM ET (US)     Profile for Whalerdan  Send Email to Whalerdan     
Wonder if a 2 stroke would do better than that as (I assume) it should be a lighter motor.
Clark Roberts posted 07-13-2003 07:28 AM ET (US)     Profile for Clark Roberts  Send Email to Clark Roberts     
Currently I am running a 1998 Merc 50 on a 1977 Montauk and here is some data: 1.87:1 lower unit ratio swinging a 12" pitch Quicksilver SS prop; 34mph at 5500 WOT; cruise at 20-28mph; approx 5 mpg avg; good hole shot with one aboard, ok with two, not so good with 3 or 4 adults; will cruise nicely with 4 adults however and all around good runner...not for skiing etc! Strong suits; light weight (200 lbs), shallow draft, nimble handling... Happy Whalin'.. Clark.. Spruce Creek Navy
elaelap posted 07-13-2003 06:00 PM ET (US)     Profile for elaelap  Send Email to elaelap     
'71 Katama 16/17; bottom paint; Yamaha 50 hp "High Thrust" (like a "Bigfoot"); 13" pitch prop; 30.5 mph GPS with two aboard; quick out of the hole with one or two aboard, sluggish with four big guys; can't measure the fuel use trolling for hours 2.5-3.5 mph, 1.25 gallons per hour cruising averaging 15 mph. Motor weighs 243 lbs. I'm very pleased with this rig for my uses (salt water fishing and cruising, no skiing or wakeboarding). Damn expensive though...I lucked out and exchanged work for the motor, and got a five-year warranty too, which I love since I've already put 134 hours on the motor since March.

Good luck,


rwest posted 07-14-2003 06:31 AM ET (US)     Profile for rwest  Send Email to rwest     
I have a refurbished 35 y.o. 16 ft Nauset which I put a new 50 2 stroke Merc on in 2001. Alone I get about 33 kts, w/2 about 30-31 kts and w/3 about 30 kts. More than that drops to upper 20's. I do a lot of patrol work in the loweer Chesapeak Bay and can run all day on about 8 gals of fuel if I am not in a hurry. It will plane at 12 kts w/ 3 onboard. I have towed several boats with it from 14-25 ft without any problem, both astern as well as doing alongside tows for putting them up to a dock. Having a monster alongside with wind blowing cna make it hard to turn with the 50 and I'm sure a 90 would handle that much better but money was the bottom line and I got the 50 with tilt/trim, all cable and controls mounted plus tanks for $4000 while a 60 would have run it up another $1000 and a 4 stroke was pushing $6000. My first Whaler back in 71 had a 4 clyender 65 HP Merc which was a gas guzzler and wasn't much faster than my current Whaler w the 50 so for the money I'm happy. If speed is what you want, then go with the 90. One other note. With the 50 I can actually run a crusing speed and talk with the guy next to me. With a bigger engine that would be harder to do.


stinkyB posted 07-14-2003 01:24 PM ET (US)     Profile for stinkyB  Send Email to stinkyB     
Thanks for all the replies!!!

Sounds like a 50 would be fine, especially considering it would be 2-3 people (including myself) and fishing gear most of the time. 30kts is plenty for me. I'm going fishing, not racing ;) Ilike the 3-4mpg too....

btw... the current motor is a '85 Suzuki DT 75. The powerhead is still solid, but like an old truck I once owned it seems that it's at the point where you fix one thing, then something else goes wrong etc. Not sure it how it was maintained by the orig. owner. I'd rather be using it than fixing it, and was thinking if I'm going to spend money on the old one, I'll weigh the options on a new one. Thanks for your input, I have some decisions to make.

elaelap posted 07-16-2003 06:23 PM ET (US)     Profile for elaelap  Send Email to elaelap     

I know the feeling. My boat had an old Evinrude two stroke when I bought her last October, which started right up, had decent compression, and seemed to have plenty of power. But I never felt secure, especially when the sea kicked up a little or I wanted to go offshore a ways...because of the raggedy condition of the hull and interior, I doubted that the previous owner had treated the motor very well either. I had a nice 6 hp Johnson kicker back then, but I didn't look forward to slogging back through weather ten or twelve miles with the six-horse if the 'rude gave up the ghost.

My new motor's a four stroke, so I'm not worried about my plugs loading up trolling at slow speeds for hours at a time. I got rid of the kicker and bracket, which took about eighty pounds off the transom...of course, now I don't have any back-up at all, so I can continue to feed my ulcers with anxiety juice any time I please.

Anyway, performance-wise I'm very, very pleased with my Yamaha 50. It's never failed to start with a turn of the key, is very quiet and incredibly economical, and shoves me and my old Katama along just fine. I'm approaching 140 hours since repowering this past March, and as time passes I'm feeling more and more secure about the motor's reliability.

If you're wondering whether to go two- or four stroke, I'll defer to others more knowledgable and experienced. I've only owned small two stroke kickers for sailboats and dingys in the past, all of which served me well. For my current uses, I'm very glad that I got a four stroke motor, and would go that way again if circumstances were the same. However, if I didn't troll very much, and if fuel economy wasn't that important, I'd certainly consider all options. As I said in an earlier post, I was (and still am) stunned at the ridiculously high costs of new four stroke outboards, from whatever manufacturer. If I hadn't lucked into a work-for-motor exchange, it would have been difficult for me to justify spending more than twice what I paid for my craft to repower with a little 50 hp motor, especially since the old Evinrude still had some life in it.

Bottom line re your query: A 50 hp outboard on a 16'7" Whaler works just fine...for me.


stinkyB posted 07-17-2003 02:16 PM ET (US)     Profile for stinkyB  Send Email to stinkyB     
Thanks man..... sounds like we're in the same boat (yuk, yuk)

My father and I plan to give the motor a good "go-over" and see how we stand before I make a final decision... at least maybe I'll get her running good enough to sell/trade... Personally I have very limited boating experience, but my father is an airplane mechanic. 2 strokes are bit less complicated than jet engines ;) so we can figure out or at least identify most serious problems.

I would definitely like / prefer a 4stroke, but unfortunately there's a huge difference in price that I probably can't afford. Leaning towards Yamaha or Johnson 50 2stroke. If I went 4 I'd probably go Suzuki.


Bigshot posted 07-17-2003 03:31 PM ET (US)     Profile for Bigshot  Send Email to Bigshot     
Good choices but 1....OMC 50hp is only a 2cyl, she aint gonna have the ooomph like a 3 or 4cyl 50hp will. Fine for a 13 or 15, but I would not buy one for a 17'.
roloaddict posted 08-24-2003 12:24 AM ET (US)     Profile for roloaddict  Send Email to roloaddict     
My '71 Katama has had a 50 merc 2S, now has a 80 Merc 2s. I have been looking at twin honda 30's for the next repower.

The 50 worked fine. The older hull always felt squirelly at anything over 35 anyway.

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