Please note this thread has been inactive for 90 days. For the best results, please start a new thread.
Results 1 to 11 of 11
  1. #1

    Unhappy 1972 65h johnson w/no power?

    I inherited a 1972 johnson 65hp outboard and tried to put it in the water and it started and seemed to run fine until I tried to give it some gas. When I cranked the throttle all the way forward the motor sounded likt it was at 1/4 throttle! NO power at all. This is what I did:
    Compression test-110psi to 120psi
    New plugs
    New fuel-50:1
    Made sure the choke was not sticking
    Fuel bulb pumped tight
    and more that I cant think of right now.
    I noticed that when the motor is in neutral and I rev the carbs they come right up. But under a load they just dont rev up. When I pulled the plugs(new ones) the two top cylinders were soaking wet with oil. The bottom cylinder was crystal clean. I sprayed carb cleaner into all three cylinders and the top two carbs bogged (as expected) when I sprayed into the bottom cylnder it burned the cleaner right up and the motor actually reved a little. So I am not sure if the two top or the one bottom is messed up. Please help!?!?!
    Also the new plugs I bought were the ones listed on the front of the block, but when i look them up at various sites the plugs listed are completely different. (yes I did try both). How do I know whats right? I think the ones online were L77JC4and the ones listed on the motor are UL77V(which is listed for a 73 V4 best I can tell). How could that be listed on my motor unless the parts are similar, which I doubt. Thanks for any help guys.

  2. #2
    Senior Tech Advisor tashasdaddy's Avatar
    Join Date
    Nov 2005
    Location
    Jacksonville, Florida
    Posts
    51,017

    Default Re: 1972 65h johnson w/no power?

    it sounds to me like you need to check spark, sounds like top coil is not firing. if this is the case. you can swap postions of the coils. make note where the wires go in the power pack. then it the bottom plug is wet, you know it is the coil that needs to be replaced. if not then add to this post, and we will check the power pack. if i'm not mistaken the both plugs work in the motor, the online is an updated version.
    FLORIDA GATORS
    TEBOW Country



    Please, NO PM's (Private Messages) regarding boat/engine problems. they will not be answered.
    That is what these forums are for. Post your questions, in the appropriate Forum.

  3. #3

    Default Re: 1972 65h johnson w/no power?

    There are three cylinders and the bottom one is the only one that is dry. I have tested spark and there is fire. All three cylinders are firing b/c when I remove one wire at a time the motor lugs(running on two cylinders). Not sure if the spark is strong enough though. How would I test that? I will try changing the coils around and see what happens. The two plugs are different though one has a gap and the other does not. So you think they will both work fine? Thanks for the help.

  4. #4
    Fleet Admiral HighTrim's Avatar
    Join Date
    Jun 2007
    Location
    Hamilton,Ontario
    Posts
    8,191

    Default Re: 1972 65h johnson w/no power?

    Get a spark tester or build one urself, just search this forum for it. I believe it should jump 7/16 of an inch with a definate blue ZAP! gl

    http://www.iboats.com/Cdi_Spark_Gap_...-view_id.38089

  5. #5
    Admiral Chinewalker's Avatar
    Join Date
    Aug 2001
    Location
    1000 Islands, NY
    Posts
    6,614

    Default Re: 1972 65h johnson w/no power?

    I'm betting the carbs are gummed up... If it has been sitting awhile they'll need to be removed, disassembled and rebuilt. A manual is a must!
    - Scott
    Share A Project Page for 1971 GW Invader Banchie 13
    http://www.shareaproject.com/pages/p...,p,433,00.html
    Share A Project Page for 1976 American 18
    http://www.shareaproject.com/pages/p...,p,404,00.html
    Share A Project Page for 1974 American 15
    http://www.shareaproject.com/pages/p...,p,405,00.html

  6. #6

    Default Re: 1972 65h johnson w/no power?

    Help! I need help on ignition wiring on 65 Johnson, 1972 motor. I dont know how to post message properly, so hve to do it this way. Thanks

  7. #7
    Petty Officer 3rd Class
    Join Date
    Jun 2007
    Location
    North Carolina Coast
    Posts
    91

    Default Re: 1972 65h johnson w/no power?

    Boutin, first of all: Don't EVER spray carb cleaner into your cylinders!!! It will destroy them, washing away all the oil.

    If you say you're getting spark in all three plugs, I agree it's a carb problem; #3 carb inlet needle valve stuck or high speed jet clogged.

    Finally, is there a powerpack on a '72 model? I thought they still used points.

  8. #8
    Petty Officer 3rd Class
    Join Date
    Jun 2007
    Location
    North Carolina Coast
    Posts
    91

    Default Re: 1972 65h johnson w/no power?

    Quote Originally Posted by boutin73 View Post
    The two plugs are different though one has a gap and the other does not.
    ??????

    never mind, didn't see the "v", probably best to go w/ the l77jc4. Surface gap plugs are notorious for fouling out.

  9. #9
    Admiral
    Join Date
    Apr 2002
    Location
    Miami Fl
    Posts
    7,459

    Default Re: 1972 65h johnson w/no power?

    I'm with Chinewalker on the carbs.

  10. #10

    Default Re: 1972 65h johnson w/no power?

    Thanks for all of the replies. I figured out the problem yesterday. The third carb had a stuck float needle. I pulled it apart and freed the needle, cleaned out the carb and whala, runs like a top! Once I sprayed the cleaner in that cylinder and it fired up, I new it had to be a lack of fuel issue. I brought her out and gave a test run. BIG difference! Now I just need to find out why I went through about 4 gal of fuel in one hour! Any thoughts on that? I think it is either leaking somewhere or it is going right through the motor and out the exhaust. There is a lot of fuel in the water when I sit idle. Thanks for all of the help!

  11. #11

    Default Re: 1972 65h johnson w/no power?

    Okay, I am an idiot!!!! Dont bother to help me figure out where my fuel went. I figured it out. Just a tip for anybody who may be as dumb as me.....make sure when you put the carb back together, you remember to put in the drain plug! It seems to hold fuel so much better that way. Thanks for everybodys help.

Similar Threads

  1. Johnson 1972 50hp top end power loss
    By rebmo in forum Johnson & Evinrude Outboards
    Replies: 18
    Last Post: July 12th, 2007, 03:39 PM
  2. Testing Power pack for 1972 50 HP Johnson
    By SeaCat-Sailor in forum Johnson & Evinrude Outboards
    Replies: 4
    Last Post: November 20th, 2004, 09:44 AM
  3. 1972 MERC 50 , NO POWER
    By luigi in forum Mercury & Mariner Outboards
    Replies: 1
    Last Post: August 7th, 2003, 07:04 PM
  4. 1972 MERC 50 , NO POWER
    By luigi in forum Mercury & Mariner Outboards
    Replies: 1
    Last Post: July 13th, 2003, 12:19 PM
  5. 1972 40hp Johnson-No power to Starter
    By boatingca in forum Johnson & Evinrude Outboards
    Replies: 1
    Last Post: June 9th, 2003, 03:54 PM
  1. iboats Forum Directory - Over 100,000 forum posts organized by topic