Steering at high speeds

Discussion in 'Bubba's Outboards' started by TN-CATFISHER, Aug 20, 2007.

  1. TN-CATFISHER

    TN-CATFISHER New Member

    Messages:
    213
    State:
    Cannon County, Middle TN
    Hey all. Does anyone have an idea as to why a boat would pull to the right when moving a higher speeds? The faster the boat goes, the more pull. The skeg is a little chewed up from hitting rocks, but it's not twisted or bent. I also have a new prop. There's no other visual damage from what I can tell.
     
  2. bwhupp

    bwhupp New Member

    Messages:
    1,680
    State:
    Belleville
    I believe that is a function for in case you get tossed from the boat, it will kill itself with the kill switch and not keep going forward but kind of cycle back towards you.

    That's what I was told once when I wondered the same thing. How much truth behind it.. I don't know. But it makes sense to me! :smile2:
     

  3. BigB

    BigB New Member

    Messages:
    125
    State:
    Van Buren, Arkansas
    does your motor have a small fin right above the prop? if so that is the ajustment for steering. loosing it up and bump it to the left. a very small ajustment goes a long way.
     
  4. Bubbakat

    Bubbakat New Member

    Messages:
    4,532
    State:
    McMinnvill
    Is this motor you refering a tiller steer or remote
     
  5. jim

    jim New Member

    Messages:
    2,579
    State:
    Jacksonville NC
    Google outboard steering torque and I think you will have your answer.Tiller steered engines are the worst because the torque is passed directly to the operator.There are devices that compensate for this as hydraulic steering does for boats with a steering wheel.The bigger the engine the bigger the prop which increases the torque.This is simply the natural power of the prop rotating to the right and trying to turn the engine.:big_smile:
     
  6. TN-CATFISHER

    TN-CATFISHER New Member

    Messages:
    213
    State:
    Cannon County, Middle TN
    Someone told me that boats are supposed to do that as well, but I just don't believe it. It would be too much of a hazard for those that don't use the kill switch like myself. If you get tossed from the boat and it starts spinning circles over the top of you it could likely kill you!

    My boat DOES have that small fin above the prop, but I thought it was just one of the anodes? So that can actually affect steering? I'll check into adjusting it, and yes my boat has a steering wheel, not tiller.

    I hit some rocks earlier this year and tore up my prop and skeg, and even took a small chunk out of the gear case. This is unrelated to the steering problem because it was doing that before, but I noticed when I spin the prop with my hand it has a very subtle wobble to it. I'm going to drain the gear case tonight and check for water in it. I guess if it's clean then I won't worry about it, but I've been wondering if this is hard on the motor or causes performance problems?
     
  7. kkyyoottee

    kkyyoottee New Member

    Messages:
    754
    State:
    Iowa
    Sorry I cant help you my little 2 hp honda doesnt go fast!! :big_smile:But I suspect your bottom fin is not straight. I also think it could be on weight proportional on one side of your boat or other.
     
  8. Bubbakat

    Bubbakat New Member

    Messages:
    4,532
    State:
    McMinnvill
    Rember when adjusting the trim tab if its pulling right adjust it to the right. I think I am right on this. Adjust it just a little at a time . A 1 degree adjustment on it will affect it more then you think.
     
  9. TN-CATFISHER

    TN-CATFISHER New Member

    Messages:
    213
    State:
    Cannon County, Middle TN
    Hey Willard I'm still holding a rain check for a trip to Tim's or Chickamauga, or was it Pickwick? I haven't been out much with the heat and all, but let me know when you want to go. It's usually weekends for me, but I might be taking a break from work soon and will have more time during the week too. PM me whenever.

    I'm going out to check that trim tab, anode, or whatever right now. I might post a few pics too.
     
  10. TN-CATFISHER

    TN-CATFISHER New Member

    Messages:
    213
    State:
    Cannon County, Middle TN
    Ok, that fin above the prop does look adjustable as there's a hex bolt that goes into the circular disk that secures it to the motor. I never would've guess that small fin would make such a difference, but it does appear that it is turned a little to the right looking at it from the back. Does anyone have a recommendation for how much, if any it should pull either direction? Should I just be able to drive with no hands?

    As for the drive shaft, it is defiantely bent as far as I can tell with the way it wobbles when turned. So my other question is whether that shaft is replaceable or if I'm looking at a new lower unit. I saw a lower unit on ebay that I think would fit for a little over 100 bucks.

    Thanks
     
  11. Bubbakat

    Bubbakat New Member

    Messages:
    4,532
    State:
    McMinnvill
    If its a merc there is a little hole on top that you access that bolt at and if its a omc it comes up from the bottom. Start that trim tab a little left of the center. Not much just a little off center.
    If the prop shaft is bent then either replace the shaft or get that lower unit you was talking about. If its in good shape 100 is a good deal on it and that will leave your old one for gear parts.

    As for the fishing trip if nothing gets throwed into the spokes We are going for an alnighter fri night on the toon and we can take you to if you want to go. Me and fish and his wife and my wife. are going. Will be at nickajack. I'll be going again here in a couple weeks on a day trip as soon as this weather gets off that 100 degree days.
     
  12. TN-CATFISHER

    TN-CATFISHER New Member

    Messages:
    213
    State:
    Cannon County, Middle TN
    I took a rubber mallet and just barely started bumping that fin and it moved. I remember it seemed to start right after I bumber a sumberged tree, but just couldn't fiugre out how barely bumping it would cause the problem. Now I know :smile2: That bolt probably needs a little tightening, but it's recessed and hard to get to.

    I hope it's not too difficult changing out that lower unit. I've never done more then basic maintenance on it.

    Hey Will, I'll pm you about gettin together. I'm working Saturdays right now but we'll figure something out.
     
  13. Bubbakat

    Bubbakat New Member

    Messages:
    4,532
    State:
    McMinnvill
    You have to use a small socket and small extension to get into it. I use a 1/4 drive with a thin socket.
    When you get ready to change that lower unit out just drive over here with the boat in tow and about an hour after we start we most likely will be through with it.
     
  14. Goldenshinner

    Goldenshinner New Member

    this may seem like a random contribution to the topic, but if your running your boat by yourself and you said its a steering model, the weight of your body on the side of the boat could cause it to plane(and steer) to the side. it might also be caused by other weighting factors in the boat ....ie which side your bat is on! my 2 cents.
     
  15. TN-CATFISHER

    TN-CATFISHER New Member

    Messages:
    213
    State:
    Cannon County, Middle TN
    Thanks for your 2 cents Stephen. I appreciate all the replies! Actually somebody else had mentioned that too, but the fact is that it pulled right no matter how many people I had with me. Next time I have it out on the lake I'll bring that mallet with me and start testing moving the fin above the prop to different positions.

    On the lower unit, that auction ended up going up to 280 bucks after shipping and I just wasn't ready to spend that much. It was supposedly like new, so it was probably a good deal, but I still didn't feel I could afford it :sad2:

    Hey bubba do you know if those prop shafts are universal or do I have to get an actual Yamaha one? I can't seem to find prop shafts that are sold seperately and not part of the lower unit. Any advice? I'm just thinking maybe the prop shaft might be cheaper by itself, and I just won't worry about the mangled skeg.
     
  16. Bubbakat

    Bubbakat New Member

    Messages:
    4,532
    State:
    McMinnvill
    Get me a serial and model number off that motor and lets see what we can come up with.
     
  17. TN-CATFISHER

    TN-CATFISHER New Member

    Messages:
    213
    State:
    Cannon County, Middle TN
    Model: C40TLRY

    SERIAL: 6H4 L 930170 T

    Manufacture date: 09/99
     
  18. Bubbakat

    Bubbakat New Member

    Messages:
    4,532
    State:
    McMinnvill
    That lower unit isn't shown as a rebuildable unit. There are no known parts that I can find to replace that shaft. You might search around in some of these old marine repair shops and find a good used lower unit.
    This strikes me as odd because they have the gasket and seal kits for those lower units but no replacement parts for it.
    I'll keep an eye out for a lower unit in my quest for other parts I may be looking for.
    If you continue to operate it with a bent shaft it will finish the other parts off in short order pretty quick so don't venture to far away without a good battery and trolling motor.
     
  19. Bigjonrigger

    Bigjonrigger New Member

    Messages:
    16
    State:
    Missouri
    Yamaha prop shafts bend easily. If you or someone you know has a dial indicator, guage blocks, and a small press, you can straighten it. The tolorance on end play is between .005 and.006. I've done several, it just takes time and patience. If you don't have the equipment, try a local machine shop. A new prop shaft and seals for the hub will cost you a couple hundred dollars.
     
  20. Grimpuppy

    Grimpuppy New Member

    Messages:
    3,556
    State:
    Concordia, KS
    Without hydraulic steering, there is little chance you will ever be able to let it run on plane with no hands on the wheel. Like the others said, adjust the trim tab. I adjusted mine on the water. Run it, stop, jump overboard, adjust, run it again, repeat until you have found the best position. Also trimming the motor up when on plane will greatly reduce the torque steer. If I am on plane with the motor trimmed all the way down, it is all I can do to hang on to the steering wheel and top speed is 35 mph. I trim it up and I can get about 44 mph and can hold wheel with one hand easy.