Silly question on boat speed/trim!

Discussion in 'Boating' started by Old Bill, Oct 30, 2007.

  1. Old Bill

    Old Bill New Member

    Messages:
    448
    State:
    Oklahoma City
    I bought a old 14' aluminum fishing boat this past summer. The 9.5 HP motor was shot, so I decided to use a new Nissan 4 HP four-stroke motor that I had previously bought for a boat I was building.

    The boat weights about 200 pounds. The motor 57 pounds, and I weigh about 190 pounds.

    When I first placed the boat on the water, I had to adjust the trim angle of the motor until the rod was all the way forward to get the bow of the boat to be somewhat level.

    With less than 20 pounds of fishing gear on board the boat, and just me, the top speed of the boat was about 6.5 MPH (per my GPS), but with a extra person in the boat the top speed increased to 8,7 MPH!

    I can increase the HP of the motor to 6 HP by installing the Nissan 6 HP carb.($130.00), and increase the top speed by changing the prop from a 7 to 8 pitch. ($60.00).

    The Nissan 4 HP motor is a detuned 6 HP motor. Actually, the Nissan 4, 5 & 6 HP are mostly the same motor except for the carbs & props. The 4 HP also has a built in gas tank.

    Any suggestions, other than getting a larger motor? Why do you think the speeds increases with a second person in the boat?

    All comments and suggestions are welcome!

    Bill
     
  2. Old Bill

    Old Bill New Member

    Messages:
    448
    State:
    Oklahoma City

  3. stumpjumper

    stumpjumper New Member

    Messages:
    1,492
    State:
    Dallas, GA
    Bill:

    It sounds to me that by getting that extra weight in the bow, your boat becomes more efficient (slightly faster) because the bow "cuts" through the water rather than plowing. I fished from a 14' (4 hp) for 15 years and had similar issues. It just took me longer to get from A to B!
     
  4. tofish

    tofish New Member

    Messages:
    3,923
    State:
    arizona
    i had same problem with a 12' jon boat until i learned to put some bricks in front of boat when by myself. just had to experiment on how many bricks so didn't overload front. was nicer to see where i was going too.
    gary
     
  5. catfish kenny

    catfish kenny New Member

    Messages:
    6,064
    State:
    Iowa
    Also maybe install whale tales/fins.I run a smaller motor and I have noticed most run tailes and that makes a diff . Also the height of your motor on your transom ....a inch from what I have experienced can mean alot and I will be dambed if I am smart enough to understand it
     
  6. catfish kenny

    catfish kenny New Member

    Messages:
    6,064
    State:
    Iowa
    It is definatly not plaining right where is bubbakat? Help this man out....
     
  7. loanwizard

    loanwizard Well-Known Member

    Messages:
    3,297
    State:
    Coshocton,
    I used to have a 9' jon that did the same thing. I put my gas tank and battery forward as well as myself. Try trimming the motor to the 2 notch and then leaning forward to get the bow down. It should do better than in the last slot.

    Good luck and I hope I made sense.... been a long day.
     
  8. jtrew

    jtrew New Member

    Messages:
    4,404
    State:
    Little Rock, AR
    I've had that problem fishing by myself in both 14' and 16' jonboats. The trick is to move everything possible to the very front of the boat. A boat will 'squat' when it starts to come out of the hole. If there's no weight in the front of the boat, it never comes down level, just stays in a squat. On the other hand, too much weight in the front of the boat, and you can't get it high enough for efficient planing. If you want to get an idea of how critical proper loading is, sit in the middle of your seat and run the boat straight. Without moving the motor, slide over to one side. The boat will turn that way. Slide over to the other side, and the boat will turn the other way. Back before they made flats boats that would run in 8" of water, someone designed a little scooter for flats use. It was kind of like a tiny pontoon crossed with a raft, except the motor was in the center, and you stood up straddling it. To turn, you leaned left or right. (That was over 50 years ago.)
     
  9. Old Bill

    Old Bill New Member

    Messages:
    448
    State:
    Oklahoma City
    Merc, Gary, Kenny, Shawn and Jerry...thank you all for your comments!

    I've got a bunch of bricks that I can place in the bow so that would be a easy fix since I mostly fish alone. I'll have to come up with someway to keep them from bouncing around while trailering. I don't want to mess up the bottom of my 50 year old boat!

    I looked in my BassPro Shops catalog and saw they have a whaletail/fin stabilizer for $29.00. If my dear wife will loan me the money, or return my VISA card, I might buy one!:big_smile:

    Thanks again,

    Bill
     
  10. Gordhawk

    Gordhawk New Member

    Messages:
    1,378
    State:
    Iowa
    Bill,
    Instead of adding bricks to the front of your boat,I would add sand bags. That way you won't have to worry about them moving around like bricks will do. Just my 2 cents worth.
    Glenn
     
  11. tofish

    tofish New Member

    Messages:
    3,923
    State:
    arizona
    i used to set my bricks in a milk crate. worked perfect for me. if you move the gas tank and battery up in front, shouldn't need a lot. just experiment how much and where to load it. also, that whale fin works great. i've used one on all my boat. wall mart sales them out west.
    gary
     
  12. Gordhawk

    Gordhawk New Member

    Messages:
    1,378
    State:
    Iowa
    Bill,
    I forgot to add,that I don't believe a whale tail will be much of a benefit on that small a motor. Again,just my 2 cents worth.
    Glenn
     
  13. Old Bill

    Old Bill New Member

    Messages:
    448
    State:
    Oklahoma City
    Thanks Glen. Sandbags would be easier on the boat's old hull for sure!

    I'll have to check around and see where a person could find sandbags. Years ago I remember that such bags were sold to place in the trunks of cars to help in ice and snow conditions.

    Bill
     
  14. Old Bill

    Old Bill New Member

    Messages:
    448
    State:
    Oklahoma City
    Well, dang! Glenn, now you tell me!:crazy:

    I just today drilled four holes in my poor little Nissan motor and installed some Davis Doel Fins! Sob!

    However, Davis states that the fins will improve overall performance, saves up to 30% on fuel, faster out the hole, and so on. I'm sure that Davis wouldn't mislead a poor old country boy, would they? :wink:

    All joking aside, it will be interesting to see if there is any different in the boat's performance with the fins. I hope to get the boat on the water next week to see. If there is no improvement in keeping the boat level, then I'll remove them. No big loss, because maybe in a year or so a larger motor might appear under the Christmas Tree!:smile2:

    Hey, Gary, I've got the bricks in a milk crate now. But, boy, that crate is hard to lift! But, I guess I could use my one-cell left in my brain and remove the bricks, and then add them one at a time to the crate in the boat! Dang, sometime I really scare myself being so smart!:roll_eyes:

    Bill
     
  15. topjimmy

    topjimmy New Member

    Messages:
    431
    State:
    AZ
    Just catch more monster cats and load THEM in the front of the boat! :wink:
     
  16. Old Bill

    Old Bill New Member

    Messages:
    448
    State:
    Oklahoma City
    Now that is the best advice that I've received!:wink:

    If only it could be true!:smile2:

    All my plans for getting to the lake soon have fallen thru, and now it looks like it will be next year before I get to try out the whale tail and front loaded bricks.:angry:

    Ah! But, there are hooks to buy and noodle jugs to make!

    Bill
     
  17. tofish

    tofish New Member

    Messages:
    3,923
    State:
    arizona
    ROFLMAO over that one cell brain remark. i resemble that remark. my son was about 7 or 8 and used to laugh at me grunting when lifting into boat. one day asked to help do something, so i told him to load up the crate of bricks. he did. empty crate, and one brick at a time. did i ever turn red. :embarassed: (out of the mouths of kids)
    gary
     
  18. oh no

    oh no New Member

    Messages:
    11,108
    State:
    Indiana
    My 19 footer has a 90 with a doefin. When I'm wide open only about a foot and a half of the boat is touching the water. My sugestion is get a 40 - 50 hp motor , stick steering and sit in the front. LOL LOL
     
  19. Old Bill

    Old Bill New Member

    Messages:
    448
    State:
    Oklahoma City
    oh no, it's obvious you are not aware of my poor financial condition!:big_smile:

    Besides, with my little 4 HP motor (soon to be converted a 6 HP) I can run all day long and use less than one gallon of gasoline!!:smile2:

    Of course, it may take me all day to cross the lake and return!!!!!:roll_eyes:

    Bill