Buy Yamaha Outboard Parts

Announcement

Collapse
No announcement yet.

70ETLH lacking power

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • 70ETLH lacking power

    Hi Guys, My 87 70hp motor starts and and runs fine at lower rpms but when i give her the spurs there is no power after about 3000 rpm. I have spark at all 3 cyls.(spark looks kinda weak but it is consistent an all 3) I did a compression check and got 125, 124, 121. There was some crap in the fuel filter when i cleaned it out so i checked the fuel pump. Pump was clean and diapfragm looked ok, no holes. Any ideas would be greatly appricated. THANKS!!

  • #2
    has it set up for a few months? if so, clean the carbs.
    Michael Babuchna

    Comment


    • #3
      batman,
      Take the boat back out and go WOT.
      Have someone check the primer bulb - if it has collapsed, then there is a fuel restriction from there on back to the fuel tank. Maybe in tank filter or vent hose crimped.
      If the primer bulb has not collapsed, then pump it several times - if the rpm go above 3000, then you have a bad fuel pump. A good way to test them when you have them removed is to blow into them - you should be able to blow in direction of fuel flow, but not the other way.
      If none of the above helps, then your carbs are probably clogged with gum/varnish - most likely high speed jets. First try doing a shock treatment with SeaFoam or RingFree - sometimes that works. Also, try removing all the jets and carb bowl drain plugs you can get to and squirt some Berryman's Chemtool into the orifices.
      If none of the above works, then time to remove those carbs, teardown, clean, and install a carb kit.
      Good luck - let us know what you find out [img]smile.gif[/img] ,
      Ken K

      Comment


      • #4
        Put in new fuel pump, motor runs great. THANKS!!!

        Comment

        Working...
        X