Over maxing H.P. rating

Discussion in 'Boating' started by crazy, Dec 7, 2006.

  1. crazy

    crazy New Member

    Messages:
    2,090
    State:
    Kansas CIty, MO
    Think there would be any harm in putting a 140-150hp motor on a boat rated for 120hp?The boat is 20’6” with .100 gage aluminum hull and .125 gage on the transom. Least that’s what I think it is. They don’t make the boat anymore and when I called the company that produced it the guy in the shop could not remember. But he did say that it would probably hold it. :big_smile:
     
  2. Catter

    Catter New Member

    Messages:
    181
    State:
    Osceola, Arkansas
    Might want to check your local laws, if I remember correctly you could get in trouble if they wanted to push the issue. (at least here in Arkansas)

    Joe
     

  3. FishBrew

    FishBrew New Member

    Messages:
    329
    State:
    North Texas
    plus why would you want or have to?
     
  4. Mark J

    Mark J New Member

    Messages:
    9,407
    State:
    Four Oaks, NC
    Your boat, your life.
    I'm sure maximum horsepower ratings can be exceeded but by how much? Where is the cut off point?

    It's not always the horsepower that is the limiting factor, its weight capacity.


    Personally I think an aluminum boat is the last boat material I would choose to play with exceeding maximums for various reasons.
     
  5. three_rivers

    three_rivers New Member

    Messages:
    688
    State:
    Tupelo Ar
    It would be a risk you are willing to be prepared to take. Going over the hp rating by 10hp or so i've heard of but your talking about 30hp or more. In some states i believe it is against the law. I do know in tourneys the boats hp ratings can't be exceded. Me personally i'd go with whats posted on the boat.
     
  6. crazy

    crazy New Member

    Messages:
    2,090
    State:
    Kansas CIty, MO
    I've thought about the weight issue. The motor that's on the boat now is a 115 yamaha 2 stroke weight 358 pounds. The 140 that I would like to put on it is 410 pounds. From the same company as the 140hp there motor that is 115hp weighs in at 416 pounds. The yamaha 4 stroke 115 is 402 pounds. Either way I'm going to end up putting a 4 stroke motor on the boat and the weight of the motor is going up. Why would I want a bigger motor more displacement and running the same speed now at a lower RPM.
     
  7. Bobpaul

    Bobpaul New Member

    Messages:
    3,039
    State:
    Supply NC
    Keep an eye on the upper corners of the transom. You might want to consider reinforcing the transom at the port and starboard contact points to the hull.

    Always travel with a motor support.
     
  8. riverratmatt

    riverratmatt New Member

    Messages:
    52
    State:
    ky, totz
    in some cases max horsepowers are a joke mine forinstance has a max of 40 hp but i dont thing it would be safe with more than 25hp cnsidering its size.
    so i would recomend going under the max
     
  9. Katmandeux

    Katmandeux New Member

    Messages:
    1,618
    State:
    Checotah, Oklahoma
    This sounds like a Darwin Award in the making.:big_smile:

    Okay, not really, but that rating is there for one reason: to keep you alive. At the very least, you owe it to any passengers you might have to be the best, most responsible "captain" possible. Don't do it. Please.
     
  10. zappaf19

    zappaf19 New Member

    Messages:
    1,574
    State:
    Monticello,IN
    In Indiana if you have over powered the boat you get a ticket. Yes they do look at the little plate from time to time.
    Bill
     
  11. JAYNC

    JAYNC Active Member

    Messages:
    1,312
    State:
    Newport N.C.
    I totally agree, My boat is rated for a 90 but I have a 75 on it and it does great. Its just like speeding in a car, yeah you might get there 2 minutes faster but is it worth the risk. I would hate to see a boat jump a wave and see the transom break off.
     
  12. jim

    jim New Member

    Messages:
    2,579
    State:
    Jacksonville NC
    Listen to Mark, aluminium is the last thing you want to over stress.More weight,plus vibration ,plus over powered is a recipe for disaster.I am curious why the 4 stroke?There are plenty of 2 strokes that in test after test have proven MORE economical than the 4s at normal operating speeds..Mercurys' OPTIMAX comes to mind.The new 2 strokers are very very good at fuel economy and generally give you a better hole shot and top end.The 2 strokes are particularly economical in the cruising range you seem to prefer.If I were you I would carefully research ALL the engine options.You may be able to get more HP,and still stay within your approved transom weight range.The Coast Guard will flat out ticket you because that is one of the things they DO look at if they inspect you.A 2 stroke 120 would give you a little more HP and with a proper SS prop might boost your performance a little,(Check the RPM range of any engine) and still be in the correct weight range.BASS and WALLEYE BOATS magazine has done many of these tests as has Trailer Boats.Go to their websites and you can read the articles.I would love to have a new Mercury VERADO 200HP but it is close to 100lbs to much for my transom so I have to stick with my Optimax which isn't painful at all.Better that than find the VERADO and transom sitting next to me at the console.:eek:oooh: :confused2: :tounge_out: :big_smile:
     
  13. crazy

    crazy New Member

    Messages:
    2,090
    State:
    Kansas CIty, MO
    Why the 4 banger. Because I don't like the motor that's on there now. I want a warmer blooded motor. One that likes to start when it's 17 degrees outside. This motor is also hell on fuel. Now yes I can probably play around with prop pitch to find one that is better suited for this boat. As far as the coast guard plate that is on the boat. There is no max weight listed for the motor... just says max HP 120.

    This is what it kind of looks like... Although Duracraft has been bought out by another company. So they don't make the boat now. But it is a Duracraft "Cat Master" Looks kind of like there bayboat just better suited for catfishing the rivers.
    http://www.duracraftmarine.com/BayBoats.htm
     
  14. AwShucks

    AwShucks New Member

    Messages:
    4,532
    State:
    Guthrie, Oklaho
    Why a four banger... because in some states, think California, the Corp of Engineers won't allow a 2 cylinder motor on the lakes. Bad as it is, if California starts something, the rest of the nation follows.. look at smoking in bars and resturants. Where did it start?
     
  15. Phil50

    Phil50 New Member

    Messages:
    42
    State:
    Il
    You might also think about insurance. My State Farm agent says they won't insure a boat that is over-powered.
     
  16. SkiMax

    SkiMax New Member

    Messages:
    2,012
    State:
    Rising Sun, IN
    Also, you would probably have to do it yourself. I don't know of any reputable boat mechanic or store that will overpower a boat. So ur going to have to rig it yourself. I would just stick with a smaller motor. I bet that 120 makes u go faster than any of the fish can swim!
     
  17. jim

    jim New Member

    Messages:
    2,579
    State:
    Jacksonville NC
    Understand you don't like whats on there now.For everybodies info there are two strokes that meet the CARB law requirements for California.In fact I think the new E-Tecs have been given a 4 star rating.If your old engine is carbuerated then it is a gas guzzler no question.What I am saying that if you are getting a new engine don't discount 2 strokes because the new generations are just as fuel efficient as 4 strokes and some are more so.Secondly they weight less than 4s.Finally the CG has a data base of boats which you and they can go to that tells ALL the specs on your boat.That boat has a max weight limit for the transom.As far as cold starting the new generation of direct injected 2 strokes fire on the first turn of the key.I have 8 boats here in my Navy boat crew and we use E-tecs and they are the same way first turn of the key.Before you commit to 4s research the new 2s.
     
  18. Mark J

    Mark J New Member

    Messages:
    9,407
    State:
    Four Oaks, NC
    Bobpaul is in the business. He told me some time back to seriously look at the E-Tec before I dropped the money for a 4 stroke.

    I've fished with the 4 strokes and love them but I dont own one. I really dont think the verdict is out yet on a 4 stroke. It will cost alot more to rebuild a 4 then a 2. There is alot more moving parts in that 4 stroke too. More parts to fail.

    In the situation I would have to have someone SELL me one or the other.
    Once the 4 strokes came out strong the 2 strokes got alot better.
     
  19. Bubbakat

    Bubbakat New Member

    Messages:
    4,532
    State:
    McMinnvill
    Four strokes aren't new to the market. I would opt for the new e-tech and as for over powering that boat if you have an accident and hurt or kill someone you can better bet that someone will measure the boat from tip to stern and tell you what size motor that boat was built to handle.

    Its your boat and your desicion but I will try to keep and Eye out to the location you are fishing so I can go some where else because it will be a disaster waiting to happen.
     
  20. Bobpaul

    Bobpaul New Member

    Messages:
    3,039
    State:
    Supply NC
    I told him what I told him because he's going to put that motor on there.

    I know a guy that overpowered a boat that was only rated for a 6 hp and got it up to 21.5 mph. Now that's an idiot!!!