Logo
Results 1 to 5 of 5
  1. #1

    Default Power problems with 1977 85hp Johnson

    I have a 1977 85hp Johnson outboard motor that will be running along at full power then for no apparent reason cuts back to approx half power. Sometimes it's got full power sometimes not. It seems to be either full or half. It doesn't slowly lose power. I'm not sure though if I should say it's losing power or RPMs. Any experience like this out there?

  2. #2
    Join Date
    Sep 2010
    Location
    ontario
    Posts
    14,886

    Default Re: Power problems with 1977 85hp Johnson

    Have you test run with cowling off the motor ?---Test run with another tank and hose ?----If it is cutting back to half power it surely is loosing RPM !

  3. #3
    Join Date
    Apr 2010
    Posts
    4,050

    Default Re: Power problems with 1977 85hp Johnson

    Do a cylinder drop test on it when it happens.

  4. #4

    Default Re: Power problems with 1977 85hp Johnson

    Quote Originally Posted by racerone View Post
    Have you test run with cowling off the motor ?---Test run with another tank and hose ?----If it is cutting back to half power it surely is loosing RPM !
    Yes it is losing rpms but what is causing it? If it is a leaking or obstructed gas line why would it always be the same power? It should be acting starved for gas and losing power in an irregular way. When it cuts back in power it holds there instead of slowly powering out. It will hold for maybe 10 minutes like that and then it might suddenly find it's power again for 5 minutes.

  5. #5

    Default Re: Power problems with 1977 85hp Johnson

    Thanks, I'll try that when I take the boat out.

Similar Threads

  1. 85hp 1973-1977 Johnson.
    By GaryOutland in forum Johnson Evinrude Outboard Forum
    Replies: 4
    Last Post: 05-27-2016, 07:34 PM
  2. 85hp 1973-1977 Johnson. what do I have?
    By GaryOutland in forum Identifying Model / Year / Horsepower
    Replies: 8
    Last Post: 05-27-2016, 11:27 AM
  3. 1977 Johnson 85hp
    By Rooky in forum Identifying Model / Year / Horsepower
    Replies: 2
    Last Post: 07-22-2015, 12:38 PM
  4. 1977 Johnson 85HP Power Tilt and Trim unit
    By markt in forum Johnson Evinrude Outboard Forum
    Replies: 4
    Last Post: 07-31-2013, 09:18 AM
  5. 1977 85hp johnson problems starting
    By waxie1986 in forum Johnson Evinrude Outboard Forum
    Replies: 12
    Last Post: 07-30-2010, 07:54 AM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •