rated for 80hp, can I go 115hp?

[huntxtrm]

I've got a 86 model aluminum bass tracker. It's coast gaurd plate says max 80hp. Can I put a 115Hp merc on it? Will It be legal? Will it hold if i beef up the transom? It has a 45 hp merc on it now. It is a semi v hull, almost a flat bottom.

 

[trendsetter240]

Re: rated for 80hp, can I go 115hp?

There is no Law that I'm aware of that you'd be breaking. It would certainly be dangerous and not insurable. If someone were injured or killed in an accident with that boat you would likely be found negligent.

Thats almost 50% more horsepower than it's rated for. The rating is there for a reason.

 

[huntxtrm]

Re: rated for 80hp, can I go 115hp?

How do they come about the rating? Is the weight of the motor, or just the hp? I don't see how it would be dangerous if i didn't use all the available hp, as long as there were not a big difference in weight. I was planning to reinforce the transom if I do this. It is a 17' long boat, why would it only be rated for a 80hp motor? I don't have to do it, I just got a good 115 merc setting here already, thought it might me good replacement?

 

[trendsetter240]

Re: rated for 80hp, can I go 115hp?

How do they come about the rating? Is the weight of the motor, or just the hp?

They use a number of factors to determine max hp for a boat. The most simple being Length of the boat x Width of the boat at it's widest part X 2 - 90. This formula works for most boats. (L X W X 2)-90 = Max HP

They also use safety and handling test such as running the boat at full throttle towards an obstical and then cranking the steering all the way to try and avoid the obstical at the last moment.

The run the above test over and over again, increasing the HP each time until the boat can no longer remain in control during this manuever.

So by overpowering you may end up with a boat that losses control in an emergency situation, is too stern heavy or simply cracks your transom in two the first time someone gives it WOT.

I would not risk it.

 

[JB]

Re: rated for 80hp, can I go 115hp?

I question whether it is safe to put 80HP on that flimsy tinny.

If you are looking for someone to hold your beer while you do something dangerous you aren't lilkely to find him here.

 

[Frank Acampora]

Re: rated for 80hp, can I go 115hp?

You can do almost anything you want, but if you live in a state where the local Fish and Game are stringent, then the least that will happen is you will get a very expensive ticket.

For many years now people have been overpowering boats and changing engine hoods to reflect the max rated HP of the hull. The Fish and Game are not stupid and may notice.

Me: I have a specialty hull originally rated for 35-40 HP and with modifications, I have mounted a 125 on it. However, It is my experimental boat, not my daily ride. I only use it when there is no one on the river.

If you do "Beef" up the transom, be aware that not only the transom needs to be reinforced, but the transom needs to be tied into the rest of the hull so the horsepower forces are transmitted into the whole hull. Typically, this means more and thicker knee braces and corner braces.

 

[Silvertip]

Re: rated for 80hp, can I go 115hp?

I take it "insurance" is not in the picture here. 1) your insurance company will not insure an overpowered boat. 2) If you don't bother telling them that you have 115 on an 80 rated boat they will issue a policy. But -- if you have an incident, whether or not it is your fault, the insurance company will leave you holding the bag since you lied on the application. 3) The attorneys will have a field day and all of your stuff will belong to someone else. But then if you own nothing of value, you will only lose your car or truck and the boat. Think about this situation carefully.

 

[4JawChuck]

Re: rated for 80hp, can I go 115hp?

The insurance issue is a USA problem only, USCG certification is not a requirement in Canada and hull rating is not considered in the insurance policy. When I insured my boat they didn't even ask what the hull rating was, they only wanted a serial number for the motor and boat for replacement evaluation. Insurance is calculated on the motor HP and boat size to give a HP per foot multiplier.

I have a 90Hp on my 80Hp rated boat, they couldn't care less and I even asked if this was allowable. The insurer said it is done all the time for the simple reason that many people build or have a custom made boat and it is up to the consumer to ensure safety of the equipment.

The way it should be don't you think?

BTW its getting a 225 ProMax this winter after I reinforce the hull and transom to handle the power increase and upgrade to hydraulic steering. It should cost a fortune to insure!

 

[Bass Tracker TX17]

Re: rated for 80hp, can I go 115hp?

I can not imagine a 115 on a Bass Tracker.

Can you do it ?? Sure.
But i will tell you one thing. Handeling goes south exponentially as speed
gets up there. trim is sensitive and if you dig the nose when you trim down for a corner your going to drive that baby like a sub.

your looking at 100 pounds diff ( ROUGH) between the 2 motors.

Free board isn't great. Just a lot of what if's.

 

[Bob_VT]

Re: rated for 80hp, can I go 115hp?

This will not be endorsed by iboats. We do not advise anyone regardless of country or area to do what the USCG consider's unsafe.

No further discussion this post is closed.