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Author Topic:   335lb Suzuki 70hp too heavy f/my 15' Sport?
SuburbanBoy posted 03-01-2001 12:45 AM ET (US)   Profile for SuburbanBoy   Send Email to SuburbanBoy  
Looking at the Suzuki 70hp 4cycle, it weighs about 335lbs. Will my stern sit too low with this much weight? Perhaps this is not too far over weight, as back in 1976 or so the run of the mill 70hp may have weighed about the same? Also considering a 60hp Mercury 4cycle at about 235lbs. Mercury is less expensive, Suzuki has a 6 year warrenty, and is injected. The big advantage for the fuel injection is the reduction in long term storage based fuel system problems. My fuel injected motor cycle will start and run just great, even if left alone for 4-6 months. I don't think the carb versions can survive that long without some fiddling.

Thanks for all input.

Tom W Clark posted 03-01-2001 12:52 AM ET (US)     Profile for Tom W Clark  Send Email to Tom W Clark     
My 1979 15' had a Johnson 70 which weighed 222 lbs as I recall. Quite a bit less than the Suzuki 4 stroke. That boat of mine really flew. I was suprised that the 15 even had a 70 hp rating. Now somebody correct me if I'm wrong, but didn't the 15' have a max hp rating of 75 when it first appeared? Seems like I remember that bit of trivia from somewhere.
SuburbanBoy posted 03-01-2001 01:00 AM ET (US)     Profile for SuburbanBoy  Send Email to SuburbanBoy     
75 hp would actually open up the options! But again, how is the handling with the 335lb slug on the stern? Will it constantly take on water when dropping off plane?
russellbailey posted 03-01-2001 07:09 AM ET (US)     Profile for russellbailey  Send Email to russellbailey     
I had thought the motor on our Striper 15
was 320 lb. But I just checked and it is
actually 250 lb (1988 Evinrude 70 power

The Striper has a little different setup
than the Sport, where the fuel tanks essentially have to be in the back. With 18 gallons of gas and the battery back there, plus the driver and a passenger in the rear seat, it is stern heavy. For waterskiing, the boat gets up a lot faster having someone sitting on the bow deck.

With our current weight, we'll get some water in the splash well coming off plane sometimes. When my wife (~125 lb) climbs in over the cavitation plate, it is quite noticeable in the boat trim.

So, in total, it might be ok if you can move your fuel tank forward (under the seat of the Sport, for example).

Ours is stern heavy enough I'm considering moving the console and drivers seat as far forward as I can (about another 18") to better balance.

SuburbanBoy posted 03-01-2001 10:48 AM ET (US)     Profile for SuburbanBoy  Send Email to SuburbanBoy     
It is amazing what the cost of a 4stroke is (about 90 lbs in this category). If I could live with "only" 50hp, there are a variety of choices around 220lbs. Have yet to find anyone who has been exposed to the Merc 60 4stroke on the water.


Maerd posted 03-01-2001 02:01 PM ET (US)     Profile for Maerd    
I would not worry about water in the boat. I have had 13 w/40 and Montauk w/100 and always had some water in the boat (either from the front or the back) from jumping waves / turning sharply or slowing down fast. Chuckle - It may have been the way I drove them. I would just turn on pump or pull plug and it drained out. I bought war surplus water proof bags and they kept everything perfectly dry.
hooter posted 03-01-2001 06:00 PM ET (US)     Profile for hooter    
Subba bubba, foget all dat bean kurd stuf your girlfriend's been feedin ya an slap a lil ole 2-stroke 70 on back o'that baby and ride! Mo power, mo speed and less money. A lil smoke won botha anyone but the ole ladies down at the nursin home. If girlfriend holds her nose, go getcha a new one! In anotha ten yeahs maybe some rocket scientist will have figured out the 4-stroke weight to hp thing. It ain't there yet at the small end o things where yous at.
jimh posted 03-01-2001 07:40 PM ET (US)     Profile for jimh  Send Email to jimh     
In the same vein as hooter's post, but without the eye-dialect:

The Yamaha 70 HP 2-stroke weighs only 235 lbs.

I know a 4-stroke will emit less pollution, but at some point the additional fuel consumption of carrying an extra 100-lbs around must eat up some of the advantage.

I never thought of this before, but when you are trailering, dragging an extra 100-pounds of boat around must ADD to the total pollution!

whalernut posted 03-01-2001 07:57 PM ET (US)     Profile for whalernut  Send Email to whalernut     
I believe someome with a new Montauk on the forum has a Merc. 50h.p. 4-stroke on it and sais it runs great! I think it is Dick? The 60h.p. version is only slightly different, and something like 10 pounds heavier. It sounds like the Merc. 50 h.p. 4-stroke might be you`re ticket. Regards-Jack Graner.
cbean posted 03-01-2001 08:15 PM ET (US)     Profile for cbean  Send Email to cbean     
yOU MIGHT WANT TO SEE SOME RESOPNSES FROM A SIMILAR POST "REPOWER SPORT 15" I RECIEVED IN DECEMBER. I LEFT WITH THE IDEA THAT IF YOU WANT TO PULL ANY ADULT SLOLAM SKIERS STAY WITH THE 70. Does any one know if there is any difference in newer vs older yamaha 2 cycle 70's as far as pollution or effieciency? how far back can you go and still get a reliable "modern" two stroke?
Dick posted 03-01-2001 08:30 PM ET (US)     Profile for Dick  Send Email to Dick     
I run a Merc 50 4 stroke on my Montauk. Loaded, downriggers, electric trolling motor, 27 gal fuel me, the wife and our spaniel first mate 34 mph with no wind on the GPS. Think it is a great motor.
Should be real nice on that 15.
Mike in Seattle posted 03-02-2001 12:34 AM ET (US)     Profile for Mike in Seattle  Send Email to Mike in Seattle     
I have a '84 15 center console with a 1995 75hp Mercury hanging off the back; it weighs over 300lbs. I'm sure the extra 5hp is not worth the extra weight compared to a 70hp but to answer your question, it does sit low but pops right up on plane runs fine. It rarely takes any water over the transom except occasionally when backing down. I've gotten it up to about 46 mph by my GPS but I usually chicken out before I'm sure it's topped out.

For reference, I pulled the plug once to see how she floated; with that big motor and about 10 gallons of gas back there, I was surprised that it floated with water still a couple inches below the motor well. The bottom of the motor well drain holes were just at the surface of the water.

I'm looking at repowering to reduce weight so all the input is interesting; I don't see a downside to taking a big chunk of weight off the transom.


Kim posted 03-10-2001 06:06 PM ET (US)     Profile for Kim  Send Email to Kim     
I have a DF 70 on my montauk17. the best thing I ever did !!! you might look at a DF 50. 238 lbs . the 70 is 335 lbs... on my boat runs 38 mph. top speed. cost on the DF 50 $5377.00 the DF 70 $6426.00 hope this helps.
Kim posted 03-10-2001 06:06 PM ET (US)     Profile for Kim  Send Email to Kim     
I have a DF 70 on my montauk17.
the best thing I ever did !!! you
might look at a DF 50. 238 lbs .
the 70 is 335 lbs... on my boat
runs 38 mph. top speed. cost on
the DF 50 $5377.00 the DF 70
$6426.00 hope this helps.
Whaletosh posted 03-12-2001 08:44 AM ET (US)     Profile for Whaletosh    
You might want to consider the new Mercury 60 HP 4-stroke; same block as the 40/50 and weighs only less than 250.


dgp posted 03-12-2001 12:02 PM ET (US)     Profile for dgp  Send Email to dgp     
The 30/40 HP Mercury four stroke is a 3 cylinder, 747 CC engine.
The 40 Big Foot/50/50 Big Foot/60/60 Big Foot HP Mercury four stroke is a 4 cylinder, 995 CC engine. The standard engine weighs 236# while the Big Foots weigh 252#. Don

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