Bought new boat, engine is bigger than recommended??

[Skyla316]

I bought a 1987 Sportcraft 16' center console. I believe they call it a 160 fisherman.

Well it came with a 80's 115hp inline 6, but on here it says the rated max HP is 90hp?

I need engine work done but what are the down falls of having boat being over powered? I mean this boat weighs 1350 dry, I'm new to the boating seen.

All help is much appreciated.

 

[Skyla316]

Re: Bought new boat, engine is bigger than recommended??

more less should I look for another smaller motor?

 

[Timestep]

Re: Bought new boat, engine is bigger than recommended??

I would be worried about insurance ?

 

[emckelvy]

Re: Bought new boat, engine is bigger than recommended??

Get a 90 hp cowling and lower "horseshoe" wrap-around and you're good to go!

Realistically, a 115 might be a bit more hp than that hull really needs, but at 1350 lbs it sounds like a fairly substantial boat. If operated with a modicum of caution, I wouldn't say that the boat is dangerously overpowered.

Insurance-wise might be the issue. However, a 90hp Inline Six is identical in appearance (except for the HP decals) and weighs the same (around 300 lb). All the Magic happens inside the block!

If you're concerned about getting hassled from the local Gendarmes or insurance company, swap cowlings; re-decal your existing cowlings; or offer-up a trade for a 90hp. Some poor water skier might be happy to make the swap!

The 90hp would be a tad more economical, as well. But the biggest difference you'd notice would be at the top end, if you're just cruising around the diff in fuel economy wouldn't be as much.

HTH..........ed

 

[mr 88]

Re: Bought new boat, engine is bigger than recommended??

Besides the above posters ideas you cold also remove the hull info plate. If that was ever questioned all you got to say is I bought it this way and I know nothing about a metal plate.Then there is also the technical end of it. Was the HP rating for the boat done after they changed the hp rating on outboards from the crank to the prop ? There are very few that insure there boats around my area including me so that would never bother me. BTW I have a 15' boat rated for 110 hp in 1966 [ which was the largest HP made then] and I am running a 150 on it,no problem.

 

[wired247]

Re: Bought new boat, engine is bigger than recommended??

If you have the boat insured and you cause an accident there is a chance your insurance company would disavow knowledge of your existence.

If you have water cops where you are who check that sort of thing ( they dont here ) then you could conceivably get a ticket.

In practice there is no difference in weight between a 90 and a 115 and most folks couldnt tell the difference between the two on the water. Engine weight is much more of a factor in how a boat handles than a few HP difference.

Put 90 cowlings on it and call it good if it bothers you.

 

[Skyla316]

Re: Bought new boat, engine is bigger than recommended??

Not sure what year they changed the hp rating but my motor is a 1985 115hp. So as far as weight of the motor goes I should not be worried cause the 90hp and 115hp weigh the same? Then is it possible my boat was rated for a 90hp 4 cylinder? Doesn't say on the iboats spec.
Also my boat has no info pleate and the only screw holes I see that are not in use was for accessories.

 

[Skyla316]

Re: Bought new boat, engine is bigger than recommended??

I fudged up on the weight. The boats net weight is 1200 lbs not 1350.
And I seem my exact boat for sale in NC with a 85 hp 4cyl Yamaha, so I'm wondering if the max hp rating of 90 hp is meaning a 4cyl not inline 6??

 

[Skyla316]

Re: Bought new boat, engine is bigger than recommended??

Ok now I'm confused.!!
Iboats is saying my 87 Sportcraft 160 fisherman is 1360 lbs but nada is saying 1200!!??

Boat: 1987 Sport-Craft Boats 160 Fisherman

I'm just confused

 

[White Boat]

Re: Bought new boat, engine is bigger than recommended??

If you insure your boat and you have to give engine particulars (serial # & model #) they will know what it is regardless of you changing cowling and decals, your insurance could be voided!

As far as weight goes a 4cyl to 6 cyl does not make a lot of difference. Now if you go to 4 stroke from 2 stroke... big difference!

Personally I would consider the age and condition of a vessel and it's transom. If you dont care if you crack your transom and are willing to pick that bill up, just to have a couple more knots of speed...go for it!

 

[Skyla316]

Re: Bought new boat, engine is bigger than recommended??

No I definitely care about the boat. It is in near mint condition so I don't want to have a motor that will effect my transom.
So iboats spec sheet says max 90-95hp but doesn't clarify if 4 cyl or 6. And others say the 90 hp inline 6 weighs the same, and you just said there really is no weight difference in 4-6 cylinder. So I'm confused of what you are implying about my transom weakening if my boat is suited for a 95hp motor?
They weigh the same as my 115, are u saying the torque of the 115hp will weaken my transom?

 

[White Boat]

Re: Bought new boat, engine is bigger than recommended??

The amount of cylinders does not matter. A 6 inline will have smaller bore than a v4. and it could weigh exactly the same.

When a boat is built they do a break test on the transom to verify the max load in thrust and weight.

A. they don't want you to overweigh the boat. ie. max weight could be people, gear, fuel, engine equalling 1200 lbs.
B. they don't want you to overthrust the transom. max thrust from standstill.

My opinion is if you are spending money on the engine to fix consider this... what would happen if your insurance was voided and/or you were targeted for tickets?

 

[wired247]

Re: Bought new boat, engine is bigger than recommended??

No I definitely care about the boat. It is in near mint condition so I don't want to have a motor that will effect my transom.
So iboats spec sheet says max 90-95hp but doesn't clarify if 4 cyl or 6. And others say the 90 hp inline 6 weighs the same, and you just said there really is no weight difference in 4-6 cylinder. So I'm confused of what you are implying about my transom weakening if my boat is suited for a 95hp motor?
They weigh the same as my 115, are u saying the torque of the 115hp will weaken my transom?

The is almost no perceptible difference between a 90 and a 115 . If anything Mercury 90's are closer to 100 HP and their 115's are closer to 110 HP. You could put a 150 or more on there and it would likely be just fine if your transom is in good shape. It makes no difference whether its a 4 or 6 cylinder. Horsepower is horsepower.

How many people do you know that have ever been ticketed for overpowering a boat. In 34 years of playing with boats I cant count zero.

 

[Skyla316]

Re: Bought new boat, engine is bigger than recommended??

I'm just trying to find a suited motor for my boat, if the 115 I have now will hurt my boat then it's coming off. I just don't want my boat to be a dog as to having a small motor. So my boat weighs between 1200-1360lbs (nada says 1200 but Iboats says 1360 lbs) so if a 90-95hp is what needs to be on it and nothing more than ok.
Now are the older 80's motors under or over rated in hp?
Is it possible my 1985 115hp inline 6 is equal to today's 90hp motors and weigh about the same?
Just wondering when iboats put in their spec sheet that my boat is rated for a max 95hp motor was that at today's standards of horse power or in 1987?

 

[wired247]

Re: Bought new boat, engine is bigger than recommended??

If you insist on going by nameplate HP then you dont need to worry about the HP difference. 1987 was well into the new HP rating era so if it says 90 HP then that is about the same as the old 115 crank rating system.

FWIW my 1100 lb 125 HP rated boat has a stout 150 pushing closer to 175 HP and its had a 225 and 260 on there in the past.

 

[White Boat]

Re: Bought new boat, engine is bigger than recommended??

Don't get me wrong, yes, the boat is capable of handling your 115, as "wired247" has stated, providing your transom is good. I just pointed out the facts that you asked for... Engines are rated exactly what they are wether it is 5hp or 150hp, there is a formula for working this out. The main difference when your boat was made is that, now boats are rated for 4 stroke engines which are much heavier than their 2 stroke counterparts. A 2 stroke engine revs much faster or quicker to a given rpm than a 4 atroke. But as wired247 pointed out HP is HP, it does not matter if you have yesterday's 115 or today's 115. The difference would be weight, yesterday's 115 would weight about 80 lbs (+/-) less than today's 115.

I just wonder why wired247 is now saying "How many people do you know that have ever been ticketed for overpowering a boat. In 34 years of playing with boats I cant count zero."

when earlier he quoted this, "If you have the boat insured and you cause an accident there is a chance your insurance company would disavow knowledge of your existence.

If you have water cops where you are who check that sort of thing ( they dont here ) then you could conceivably get a ticket."

 

[Skyla316]

Re: Bought new boat, engine is bigger than recommended??

I don't have a info plate, I was told this engine has been on this boat for years and transom seems very solid.
But I will maybe think about putting a inline 6 90hp mercury on it after I get this one out on the water to see, or even a 4 cylinder mercury as the v4 motors seem to be easier to work on but not sure yet.
I'm not sure about insuring it and not sure how the cops are in my area as this is my first boat. I live in Florida about an hour north of Tampa and will be spending most of my time out on the gulf.

Thank you everyone for their responses to my concern as it is deeply appreciated very much!

 

[wired247]

Re: Bought new boat, engine is bigger than recommended??

I just wonder why wired247 is now saying "How many people do you know that have ever been ticketed for overpowering a boat. In 34 years of playing with boats I cant count zero."

when earlier he quoted this, "If you have the boat insured and you cause an accident there is a chance your insurance company would disavow knowledge of your existence.

If you have water cops where you are who check that sort of thing ( they dont here ) then you could conceivably get a ticket."

You are mixing metaphors. In 34 years of boating since I first started piloting the boat I still have and have known hundreds of people that have owned boats and MANY of them , myself included, have had motors larger than the nameplate "suggested" . Not a single one of them has ever been ticketed for having an over powered boat. Water cops are few and far between and not a single one of them has ever looked at the name plate on any boat that I have ever seen or owned. They look for life jackets and horns and throw pillows and to see if anyone has been drinking. Many if not most states don't care what you have on the back of the boat anyway.

Insurance is different. IF you have insurance on your boat ( not required on boats that are not financed ) and you sign a contract with your insurance company stating your motors HP rating and you cause an accident, it certainly is unlikely that they will cover you. Insurance regs and state laws are not the same and an insurance contract violation is not going to get you a ticket from the water cops. I dont have insurance on my 30+ year old boat because I live in an area that I would really have to try to get close enough to another boater for it to matter. No state REQUIRES that you have insurance on a pleasure boat. Water cops just check to see if I am poaching sturgeon and carrying a horn or a flag if I am pulling a skier/tuber. No insurance is required and they dont care about whats on the back. If you moor your boat in a marina they may require insurance but the staters and the coast guard don't. If you dont have a nameplate and you want insurance then just tell the insurance company what you have. They'll insure you or they won't

 

[Timestep]

Re: Bought new boat, engine is bigger than recommended??

If there is no specification plate, and no on line definitive "manufacturers" guide. Then I would insure it exactly as it is, quoting the engine details, horsepower and serial number.

Dave

 

[Skyla316]

Re: Bought new boat, engine is bigger than recommended??

Ok I did find a plate but it is worn off, it says max capacity including persons, motor ect is 1350 lbs but the plate from what I can see doesn't say anything about max hp.