Overweight engine

morin1 · 07 January 2017, 23:54

My Zodiac Ribster LSC-530 is rated for maximum 90HP and a maximum engine weight of 348 lbs. I’m thinking replacing my Evinrude E-tec 90 HP (in-line 3, 79.1 po3/ 1295cc, 320 lbs) with an Evinrude E-tec 90HP-HO (V4, 105,4 po3 /1726cc, 390 lbs), but... this engine is overweight by 42 lbs. Since engine manufacturer can rate their engine within 10% of their real power, Evinrude claim that the 90HP-HO will deliver 99 HP, this is why I consider this model.
Anyone of you has any experience with an overweight engine? I’m afraid an additional 70 pounds (from actual engine) and 42 pounds more than the maximum weight will create more cons than pros.
A Suzuki 90HP (in-line 4, 91.7po3 / 1502cc, 341 lbs) is also an option. Do you know the real HP for a regular Evinrude E-tec 90HP and for a Suzuki 90HP? I wander if this additional 200cc will make a difference.

Thanks for your comments.

ncp · 08 January 2017, 05:13

https://www.epa.gov/compliance-and-f...data#marine-si

I'm on my phone so I was having a tough time reading the spreadsheets. There should be power in kilowatts - just convert to HP.

beamishken · 08 January 2017, 10:47

Quote:

Originally Posted by morin1

My Zodiac Ribster LSC-530 is rated for maximum 90HP and a maximum engine weight of 348 lbs. I’m thinking replacing my Evinrude E-tec 90 HP (in-line 3, 79.1 po3/ 1295cc, 320 lbs) with an Evinrude E-tec 90HP-HO (V4, 105,4 po3 /1726cc, 390 lbs), but... this engine is overweight by 42 lbs. Since engine manufacturer can rate their engine within 10% of their real power, Evinrude claim that the 90HP-HO will deliver 99 HP, this is why I consider this model.
Anyone of you has any experience with an overweight engine? I’m afraid an additional 70 pounds (from actual engine) and 42 pounds more than the maximum weight will create more cons than pros.
A Suzuki 90HP (in-line 4, 91.7po3 / 1502cc, 341 lbs) is also an option. Do you know the real HP for a regular Evinrude E-tec 90HP and for a Suzuki 90HP? I wander if this additional 200cc will make a difference.

Thanks for your comments.

Surely the 10% figure is to take account of the manufacturing tolerances which could give slightly different figures for a seemingly identical engine?
If that's the case then you could end up with an engine up to 10% below stated hp I can't see why if the engine produces 99hp they rate it at 90hp when actually they could rate it at 100hp.
I may be wrong re the marine engines but I have a pal who races karts and all the rotax engines had to be totally stock (and sealed) at the start of the season the engine supplier would dyno 20 or 30 engines and sell the better hp engines to his preferred clients (my pal being one of them) This gave the drivers a 2-3 hp advantage on the track which was a lot when your less than 30hp anyway
Personally I wouldn't Base my engine choice on an unsubstantiated claim by a selling dealer I'd be looking for dyno proof for my actual engine first
Unless there is actual evidence to prove the claim I'd be very sceptical

jeffstevens763@g · 08 January 2017, 13:11

I ran a Suzuki 90 on a 5.85 rib more than happy with performance & fuel consumption the 42 pounds still has to be carried by the 200 cc irispective of the HP +or- 10% it's still 90 HP in my book. IMO Suzuki 90

beamishken · 08 January 2017, 17:50

The suzuki will need the extra cc's as it's a 4 stroke looking at the cc's the suzuki will be working harder to produce the hp which might mean it's down on torque compared to the 2 stroke evinrude
Have you looked at the specs & specifically the torque figures as that's what matters
Although the Evinrude is 200cc smaller it's firing every stroke so in reality has a cc advantage
Don't think there is much to chose between makes nowadays I'm guessing the Evinrude is at the bottom of the hp for the v4 block so possibly not as highly stressed which may be a bonus for its life expectancy

morin1 · 09 January 2017, 00:15

Thanks for the input, to be honest my main question was; would I run into problems if I install an engine that is 42 pounds (12%) heavier than the maximum engine weight?

Phil M · 09 January 2017, 11:39

I have a 530 Pro (circa 1988) with a 115hp Merc on it. It's the current 2.1l, 358lb motor, so only 10lb above your limit. I believe the 90hp is the same engine, just pushing out fewer horses. I didn't have a max engine weight listed for my hull so had to take a flyer and assume it would be ok. It sits level and, with the console and fuel shifted up front, has no issues with weight distribution. See here for some details.

Phil M

Xk59D · 09 January 2017, 11:57

how does insurance work with doing this in your neck of the woods with ignoring the rating plate?

whilst the evinrude will have more torque the suzuki may have a different gear ratio and larger prop to help compensate for that, the rude will still have more though but the extra weight may even it out slightly.

i would also think about how good the service options are near you as a good dealer could make all the difference either way and assuming your insurance allows the extra weight.

i wouldn't personally ignore the weight plate and get the suzuki.

morin1 · 09 January 2017, 23:58

Thanks “Phil M”, very interesting engine, lots of torque, up to now I did not look for Mercury. The only reason is my lack of knowledge about the distributor. As many people already said, and a agree with that, a good dealer is to consider when you buy an engine.

BUT… I’m not going any further with this project for now.
“Xk59D” it the point. After an honest conversation with my insurance broker he confirm that overpower engine is a good reason for the insurance company not to pay in the event of an accident, he never heard about overweight engine but he admit that if it is clearly indicate on the plate the insurance company will probably use that also.
So, I will keep my thrusty, but not so powerful, Evinrude and the money for the next boat... but since my wife don't known yet...