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Results 1 to 6 of 6
  1. #1
    Join Date
    Jan 2010
    Location
    metropolis, il, us
    Posts
    4

    Default Mercury 1987 90 hp

    im having a problem with my mercury 90hp 3cly motor its a 1987 model. win i put the boat in the water and start the moter it run fine you will be going down the water for about 1 mile and the motor stop runing or loses power.can some one help me with this.
    thanks blkshp

  2. #2
    Join Date
    May 2007
    Location
    Inverary, Ontario, Canada - The Great White North Eh!
    Posts
    8,431

    Default You need to troubleshoot both

    You need to troubleshoot both the ignition and fuel systems - it could be dozens of things that will cause what you describe.

    When it loses power does it stall? If it stalls can you start it right back up or do you have to wait a while?

    Are you using fresh gas? How old are the sparkplugs? Is it overheating?
    Graham

    A "professional" is someone who gets paid for their work - it doesn't necessarily mean they are good at it :)

  3. #3
    Join Date
    Jan 2010
    Location
    metropolis, il, us
    Posts
    4

    Default yes the motor does stall and i

    yes the motor does stall and if it stop runing it will start right back up but it does not take
    gas very good and at full throul it will run at 1/2 speed.it has sat at idol for a min. and it wood go back to runing good agin thin go back to runing bad agin. i change the fule lines and im going to rebild the fule pump if this doesnt fix it thin i will look at the ignition.
    thanks blkshp

  4. #4
    Join Date
    Jan 2010
    Location
    metropolis, il, us
    Posts
    4

    Default "i have a comprasion gage what

    "i have a comprasion gage what wood a good comprasion # be (100,110, 120,?). the motor is a 1987 90hp mercury 3cly.
    thanks blkshp"

  5. #5
    Join Date
    May 2007
    Location
    Inverary, Ontario, Canada - The Great White North Eh!
    Posts
    8,431

    Default "Anything above 90 would be fi

    "Anything above 90 would be fine, more importantly you want all the cylinders to be within 10-15% of each other.

    So 95, 104, 98 would be fine while 114, 114, 92 would indicate a problem with number 3...."
    Graham

    A "professional" is someone who gets paid for their work - it doesn't necessarily mean they are good at it :)

  6. #6
    Join Date
    Jan 2010
    Location
    metropolis, il, us
    Posts
    4

    Default "cool,thanks for all your help

    "cool,thanks for all your help.
    thanks blkshp"

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