70evinrude

Discussion in 'Bubba's Outboards' started by 75evenirude, Sep 13, 2009.

  1. 75evenirude

    75evenirude New Member

    Messages:
    39
    State:
    Tennessee
    Iam seeming to have an issue on top end. Seems like I should be getting more horse power.Good compression on all three cyclinders.Rebuilt carbs
    new coils,newpower pack.When I have the control wide open it seems like
    Its only half way into it. seems like Maybe carb linkage adjustments?????
    Does the stator have anything to do with it on top end and horsepower
    Or maybe a Timing Triger???
     
  2. ~Austin~

    ~Austin~ New Member

    Messages:
    57
    State:
    Texas
    :eek:oooh:I had a very similar incident with a '77 evinrude a month or so ago. Turns out one of the cylinders was dead. The problem wound up being the power pak. The only advice I can give, is make sure you're getting spark at all of your plugs.
     

  3. Bubbakat

    Bubbakat New Member

    Messages:
    4,532
    State:
    McMinnvill
    To big of a prop will make one sluggish. The only way you can be positive about your motor running up to par or below par is to have a tach. Without that its only guess work. Has this just started or you just notice it.
     
  4. 75evenirude

    75evenirude New Member

    Messages:
    39
    State:
    Tennessee
    I was having problems out of it .And I rebuilt the carbs thinking that was the problem ,but it wasn't.I then thought it was the head gasket,so I replaced that,and that wasn't it. I replaced the coils to make sure,but that wan't it either. MY problem was When I gave it Full throttle it would cough ,n hack. Then It would pick up speed and It would run good.Find out If you pecked on power pack with screwdrive it would kick in and out.So I replaced it.Ok Now it has pretty good power.but when It was acting up it would kick in and fly.now it seems like its running like I need to smack the power pack to kick it in . BUT ITS NEW POWERPACK.

    My carbs doesn't seem to have any kind of adjustment screws.I didn't know if carbs would need adjusted now? or the timing .It runs great fire's everytime , just seems like Its not getting the carb kicked open to open all the way up .
     
  5. Bobpaul

    Bobpaul New Member

    Messages:
    3,039
    State:
    Supply NC
    Look at that little roller on the carb linkage. It's called a cam follower, because when that big cam comes down it pushes on that roller and opens the carbs.

    It has a tendancy to loose the clear plastic part of the roller, making it smaller, thus not opening up the throttle fully.

    You can see it in the first picture.

    .http://www.catfish1.com/forums/showthread.php?t=68438
     
    Last edited: Sep 16, 2009
  6. 75evenirude

    75evenirude New Member

    Messages:
    39
    State:
    Tennessee
    KK , sounds Good, because when using your hand to rev motor up a little with your hand carbs,and motor sounds good just seems to not open up all the way . I will replace it, to rule it out . thanks
     
  7. Bobpaul

    Bobpaul New Member

    Messages:
    3,039
    State:
    Supply NC
    You can also look at how it all operates. Go to full throttle, then look at where the throttle plates are in the carbs.

    If they're not fully open, then the reason could be the cam follower or the cam follower may not be adjusted to the cam properly. Part of the sync and link prosess.

    There's a raised notch on the cam. When you excellorate, that notch should meet the cam follower, dead center, then make contact and start to open the carbs.

    The process of excelloration is a slight advance of timing, then opening of the carbs to add fuel.
     
  8. Scaley Cat

    Scaley Cat Member

    Messages:
    213
    State:
    Missouri
    I've been watching this post for a few days for I to have a 70 evinrude, 1991. Sounds a lot like what mine is doing. I cant figure it out either. I have noticed that I have a little fuel leaking around 2 of the bolts that fasten the crankcase to the block. Could that cause symptoms like the ones mentioned in this post?
     
  9. Bobpaul

    Bobpaul New Member

    Messages:
    3,039
    State:
    Supply NC
    Is there any chance that you could look at the carb pics and point out which bolts you're reffering to.

    Outboard blocks are two piece. Split around the crankshaft. Bolted together, they form the crankcase, then the intake manifold is bolted to that.
     
  10. Scaley Cat

    Scaley Cat Member

    Messages:
    213
    State:
    Missouri
    These are the 2 bolt holes on the crankcase I'm talking about. There's not a lot of fuel but none the less, it's fuel. I don't see any of the others leaking. I'm assuming if fuel can get out, air can get in.
     

    Attached Files:

    Last edited: Sep 18, 2009
  11. Bobpaul

    Bobpaul New Member

    Messages:
    3,039
    State:
    Supply NC
    Take them out, dip them in a gasket sealer, and retorque them.

    There is no gasket where the two halves join together. A gel seal is used.
     
  12. larry d. grady

    larry d. grady New Member

    Messages:
    328
    State:
    north caro
    Bob paul is right it sounds like you didnt sink the carbs after you put them back on.
     
  13. 75evenirude

    75evenirude New Member

    Messages:
    39
    State:
    Tennessee
    describe sink the carbs?
     
  14. BKS72

    BKS72 New Member

    Messages:
    3,361
    State:
    East of KC
    Synchronizing the carbs is where you make sure that the carburetors are opening at the same time. Most of the time people say "link and synch" because you need to check the linkage and ensure that all carbs begin to open at the same time the cam follower starts to move with the throttle and that the linkage is allowing the throttle plates to close completely at no throttle.

    It's not very difficult and there should be a section in your book that explains the procedure for your motor.
     
  15. johndeere nut

    johndeere nut New Member

    Messages:
    134
    State:
    oldham county,kentucky
    if your carbs arent synched to open up all at the same time it will make it feel like it has no power whatsoever.readjust all linkages acording to the service manual this should fix your problem also check your timing and make sure its in time.i would say the problem is with the carbs not being synched