Swapping motors

Discussion in 'Bubba's Outboards' started by AwShucks, Sep 10, 2007.

  1. AwShucks

    AwShucks New Member

    Messages:
    4,532
    State:
    Guthrie, Oklaho
    Bubbakat, my boat is rated for up to a 90 HP motor according to the data plate. Currently I have a 50 HP Johnson on it which purrs like a contented tom cat. However, I have the opportunity to purchase a 70 HP Johnson for $300.00... Thanks to all your advice, I know what to look at on this motor... the question is, how much additional weight would I put on the boat by purchasing the 70HP.

    I cannot find any reference to a motor's weights in any of my manuals or via searching the web. If the data plate says a 90 is okay, would it be bad to go with a 70? Thanks Willard.
     
  2. Bubbakat

    Bubbakat New Member

    Messages:
    4,532
    State:
    McMinnvill
    If you can get that 70 h/p for that much why haven't you got it changed out yet. :smile2: There won't be enough weight difference to think about. What year is the 70 and I'll look in my books and come up with the weight.
    We are talking about the 3 cylinder here aren't we?
     

  3. AwShucks

    AwShucks New Member

    Messages:
    4,532
    State:
    Guthrie, Oklaho
    Willard, just ran a compression check on the 70HP Evinrude I was speaking about. It ran 108 / 108 / 105. The model number is 70773S - so I would assume it is a 70 model.
     
  4. Bubbakat

    Bubbakat New Member

    Messages:
    4,532
    State:
    McMinnvill
    That my friend is a 1977 evenrude 70 h/p Good year by the way and the compression is good. Close on all cylinders and above 100. I bet a good decarb and it would be higher.
    Now when and if you buy it if it has sat for awhile do the carbs and water pump plus the lower unit oil.
    Lawerance those carbs are finicky on the float settings and should have fixed high speed jets. That engine will fool you on how fast it can run and still stay together. Be sure and do a temp check on the t-stat and see if it is opening when its suppose to.
    with the compression like that and for that money grab it and if you don't want it let me know and i'll take a trip and come get it.:smile2:
    won't weigh 20 to 30 #s more then that 50
     
  5. chambers bd

    chambers bd New Member

    Messages:
    1,134
    State:
    Sautee,Geo
    Hi
    Man get that thing on there and you see the delight of the added h/p.
    What was that flash it was awshucks going fishing he he:big_smile:
     
  6. AwShucks

    AwShucks New Member

    Messages:
    4,532
    State:
    Guthrie, Oklaho
    My little 50 pushes the boat so darn fast I'm halfway afraid I'm gonna fall out. But, I can swap the motors and put the 50 on an old boat I have... that way its like having a spare tire. You know why I want the 70 on my boat, its simple... I'm just plain stupid. LOL
     
  7. Bubbakat

    Bubbakat New Member

    Messages:
    4,532
    State:
    McMinnvill
    Naw it ain't lawerance. Its called searching for greener pastures. I have done that for years. I have a real good 1975 --85 h/p evenrude on my pontoon and I am at this time contemplating on putting on a new 70 h/p e-tech. Don't know why that old evenrude is running great and super good shape.
     
  8. willcat

    willcat New Member

    Messages:
    2,463
    State:
    texas
    i just found a 75 horse evinrude for 350$ maybe i ought to buy a spare for the toon!!!!