hp rating questions?

i have a 1989 spectrum 1700, the hp rating is 85hp. i run a 1989 force 85 hp, the motor is tired and has been rebuilt already. im just looking for a more reliable motor. So i was going to buy a new motor but was wanting more hp. The motor i have in mind is a mercury optimax 115.

So now my question, can my boat handle the motor weight and hp increase.

next what is the weight of the 1989 force 85 hp.

ive exhausted all efforts i know of to find these answers and thanks in advance.

Re: hp rating questions?

Consider the rating like a Speed Limit Sign........ 115 in an 85 zone is dangerous, against the USCG rating obtained by the manufacturer and if you ever have an accident........ you are automatically at fault.

iboats stance is NOT to condone breaking any rules or suggesting that. iboats runs a responsible forum and business.

Re: hp rating questions?

I was just in contact with a fellow from my state who wanted to replace his 125 with a 90. His boat was rated for a 90 and after years of no problems he was stopped by the water gendarmes. Result: a 280 dollar ticket for overpowering.

And-- believe me: If you get a Merc 85. it WILL have more power than the Force.

The Force weighs around 275 with power trim/tilt

Re: hp rating questions?

thanks for help but im buying new motor and they dont make a 85 anymore its either 75 or 90. not going with 75 so i figured if i was gonna over power might as well get lil more plus when i tire of this boat and want bigger i would just have to buy boat not motor too, effectively saving myself money.

i look at test runs with simualar boats as mine and speeds ranged from mid to low 40 mph didnt think it was huge gains as for now i get around 30 mph depending on weather and water condtions.

just didnt want it to tear my boat up from being too heavy or too powerful.

that would be around hundred more pds on the boat as the 90and 115 have the same weight.

Re: hp rating questions?

I would sell both the boat and motor and buy something bigger. if you put the 90 on the boat, your still over-powered

Re: hp rating questions?

Scott Danforth said:

I would sell both the boat and motor and buy something bigger. if you put the 90 on the boat, your still over-powered

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+1 on that.

I don't know the laws in OH, but here in WI, you can't even sell an overpowered boat legally.

More and more states are passing laws on this every year.

Re: hp rating questions?

A newer 75 hp Yamaha, Evinrude e-tec or Mercury optimax will run circles around ANY old 85 Force motor.

I imagine you might be new to the boating game but, the 75 HP motors of today (specifically the 2 stokes) will tear up the older 85 hp motors due to power to weight ratio. They are not cheap but they do work.

Re: hp rating questions?

I agree with the posts above that say sell the boat and replace it. By the time you buy an 115hp opti and rig it, your will be lucky to get away with 10k invested. Alot of shops won't even hang it on your boat if its over the rated hp. If your going to keep the boat, go with what bob said. A 75hp e-tec or opti would be great for that boat. Or even a newer 2 stroke 70hp yami if you can find one.

Re: hp rating questions?

OR: If you really want to keep the hull, buy a good used engine in the size needed. Putting a new engine on an old hull just loses money when you sell. And yeah, right now you don't want to sell it, but things change. That's the only thing you can rely on. Well, death and taxes too! LOL

Re: hp rating questions?

thanks for help guys, guess ill dig in to laws of ohio and see what i can and can not do, so might have to get new boat.

Re: hp rating questions?

Frank can correct me if wrong, but I think Force was always powerhead rated (referred to as "brake HP" back in the auto industry) whereas the other mfgrs became prop rated. The difference is 10-15%.

Other thing is, if your insurance company is like mine, maybe it is a State of Texas standard form, among all the blanks to fill out are 2 very important ones: Boat HP rating, engine HP. I run a 90 on a 130 hp rated boat and my insurance with high liability limit is $18 per month!!!!!

Mark

Re: hp rating questions?

Bob_VT said:

A newer 75 hp Yamaha, Evinrude e-tec or Mercury optimax will run circles around ANY old 85 Force motor.

I imagine you might be new to the boating game but, the 75 HP motors of today (specifically the 2 stokes) will tear up the older 85 hp motors due to power to weight ratio. They are not cheap but they do work.

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Although I don't disagree with the concept, its not an apples to apples comparison. Crank hp vs prop hp. A modern 75hp powerhead is probably more like a 90 or 95hp crank. (going by the strict legal definition that everyone takes, a modern 75hp is technically violating the sticker already. The boat was rated for 85 at the crank, and a modern 75hp exceeds that. That argument is pretty much ignored though...)


Anyway....


Insurance... Every time this thread comes up, I post that I used to worked in insurance, and not once did we have a situation where engine power made any difference in who was liable, or if someone was sued because of it. NOT ONCE. I've challenged people to come back with documented proof otherwise, not 'heard from a friend' stories.. Haven't seen anything yet, so take it for what its worth.

And finally, although some states have laws regarding overpowering, many don't. There is no federal law preventing the OWNER from putting a larger engine on, the sticker is what the manufacturer has to abide by. There is a throttle control for a reason. And weight is also not a driving factor, as its entirely possible to drop a larger engine on that is lighter than what was on the boat previously. (and its also entirely possible to install a smaller HP engine, and end up quite a bit heavier than OEM. (4 stroke...)


So for the guys that say overpowering is bad, any of you drive a diesel truck? Any of you have a diesel programmer, that potentially doubles the horsepower and torque? Anyone see a problem with this?

Re: hp rating questions?

tincanman said:

d. Alot of shops won't even hang it on your boat if its over the rated hp.

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Call around and ask... I'd be willing to bet you would be hard pressed to find a shop that wouldn't gladly sell you a shiny new engine and install it, at least assuming it was within reason. (they might think twice if the OP tried to slap a 250 optimax on the back of that rig, but then again, looking at the pricetag on those, maybe not)

Re: hp rating questions?

well finally an answer to my question, but thanks anyways ive decided im buying newer and bigger looking towards the nitro 188 sport. i like to fish alot and my kids like to play on the water going to look at one in person this week to see if i like it in person as well as online.

Re: hp rating questions?

Go with a 20' and you don't have to worry about HP limits anymore.

Re: hp rating questions?

i have a 1990 spectrum 1700 that im putting a new deck in. the consoles are gone so i am making it into a center console. i am putting a 90hp mariner on it.

Re: hp rating questions?

Colin, Welcome to iboats.

Please respect our rules, including this one:

12. Please do not post to threads that have been inactive for more than 3 months UN-LESS you are the original poster. We have very active forums and any thread that remains inactive for that long should be considered "dead". It is especially confusing when there is an entirely new question posted to an old thread. This is considered a hijack. Please start a new thread of your own.