15hp 2 Stroke Johnson - Sludge on lower plug please advise!!!!!

Discussion in 'Boating Discussion' started by USMCfish, Nov 18, 2010.

  1. USMCfish

    USMCfish USMC-FISH

    Location:
    Point Loma
    Name:
    Lee
    Boat:
    Tuna Can
    • Messages:
      (1,159)
    • Likes Received:
      (106)
    I have a problem with my outboard has anyone ever had this happen? I been running the crap out of her for the last 2 months prior to that she sat for about 1 year so I took it to Sunset to get carb cleaned, etc... ran like a top, last trip out I noticed I wasn’t getting full power kind of bogging at high speed, then it progressed to get worse throughout the day, so I removed hood @ home and checked spark plugs, the lower plug was so gummed up I have no idea how it even ran, so I replaced plugs. Today took her out of south bay running fine little slow to get her going but once we took off she was fine ran about 23 mph to the Coronado bridge where I stopped and drifted for a bit, fired up and left area heading towards north island when she started running really slow again, checked lower plug and sure enough it was so loaded with crap, limped back to ramp, ran it on the hose and checked plugs every 10 minutes or so with gunk built on lower plug, cleaned with gas and re inserted with same results, a friend of mine recommended to run a full can of sea foam through her? any idea or has anyone else had this problem? The color of the sludge is tanish,
    Thanks all
    ... :hali_olutta:
     
  2. Robertle714

    Robertle714 Newbie

    Location:
    Hh
    Name:
    David Nguyen
    Boat:
    None
    • Messages:
      (101)
    • Likes Received:
      (0)
    What color is the sludge? Do u see a sign of water? Most of the time when your lower spark plug has sludge or a sign of water that means that the lower seal of the powerhead is bad. In order to replace that lower seal u must pull off the engine block
     
  3. get some

    get some So Cal Editor BD Writer

    Location:
    LBC
    Name:
    Erik
    Boat:
    Robalo 226 Cayman
    • Messages:
      (3,602)
    • Likes Received:
      (3,482)
    Is it smoking a lot too?
    Your oil mixture might be off...
     
  4. USMCfish

    USMCfish USMC-FISH

    Location:
    Point Loma
    Name:
    Lee
    Boat:
    Tuna Can
    • Messages:
      (1,159)
    • Likes Received:
      (106)
    the color is tanish... and it runs at top speed of about 5 mph when its full of sludge...
     
  5. abdiver7777

    abdiver7777 abdiver7777

    Location:
    So Cal
    Name:
    Sir2you
    Boat:
    No Name........
    • Messages:
      (2,890)
    • Likes Received:
      (588)
    check the compression of all the cylinders befor you do anything......
     
  6. USMCfish

    USMCfish USMC-FISH

    Location:
    Point Loma
    Name:
    Lee
    Boat:
    Tuna Can
    • Messages:
      (1,159)
    • Likes Received:
      (106)
    not smoking anymore then normal i am mixing 50.1
     
  7. dkd711

    dkd711 Skunk Master...

    Location:
    Huntington Beach
    Name:
    Duke
    Boat:
    "WFO SKUNK"
    • Messages:
      (3,516)
    • Likes Received:
      (18)
    If you do run seafoam, make sure to swap all the plugs after. It will foul them up big time with all the crap it burns off. Don't force the issue or you can end up killing that motor.


    Robertle714 knows his stuff. He can blow a motor like nobody's business....

    :rofl::rofl::rofl:
     
    Last edited: Nov 18, 2010
  8. USMCfish

    USMCfish USMC-FISH

    Location:
    Point Loma
    Name:
    Lee
    Boat:
    Tuna Can
    • Messages:
      (1,159)
    • Likes Received:
      (106)
    it is a premix motor a 1987 johnson... also I did run a older tank of fuel last trip out and then switched to fresh tank when it ran dry...
     
  9. @-EZ

    @-EZ Fail, try again.

    Location:
    San Diego, CA.
    Name:
    Max
    Boat:
    Trophy Pro, @-EZ
    • Messages:
      (14,383)
    • Likes Received:
      (1,849)
    I didin't notice a mechanic had already commented. Sorry bout that.
     
    Last edited: Nov 18, 2010
  10. USMCfish

    USMCfish USMC-FISH

    Location:
    Point Loma
    Name:
    Lee
    Boat:
    Tuna Can
    • Messages:
      (1,159)
    • Likes Received:
      (106)
    going to try the seafoam and if not guess it goes back to sunset, for another 200 dollar + bill....
     
  11. bloodybloody

    bloodybloody Newbie

    Location:
    Rowland Heights
    Name:
    M C
    Boat:
    Searay 17
    • Messages:
      (6)
    • Likes Received:
      (0)
    check compression...most likely a gasket failing allowing water into the head....may need a new gasket and valve work....
     
  12. USMCfish

    USMCfish USMC-FISH

    Location:
    Point Loma
    Name:
    Lee
    Boat:
    Tuna Can
    • Messages:
      (1,159)
    • Likes Received:
      (106)
    i hope that isnt the case...
     
  13. MDC

    MDC Member

    Location:
    Oceanside/CA/USA
    Name:
    Mark
    Boat:
    none
    • Messages:
      (431)
    • Likes Received:
      (192)
    Lee, check out this site:

    Welcome to LeeRoy's Ramblings

    Click on Outboard motor related articles. It is probably one of the most comprehensive sites on 15 hp Johnson outboards around.
     
  14. FINADDICT*

    FINADDICT* SKIPPER

    Location:
    California
    Name:
    Fingers
    Boat:
    Finaddict*
    • Messages:
      (1,492)
    • Likes Received:
      (236)
    i heard about the "seafoam"if it does what it says that might be the cats ass!! the post earlier that makes alot of sence. when you run the seafoam thru it will clog or gunk up the plugs ... i was having the same problem but with a bigger motor.no problem at high speeds but trolling 2.0 2.5 knts ran like crap!!! and thats about 72$for me...for six champions....on these plugs there is a crush washer,and also they have to be indexted meaning to line the fire up with the injector as close as you can.meaning i cant use the plugs twice because once the washers are crushed it goes way past the point for indexing.due to torque specs...maybe you could just clean yours up.
     
  15. USMCfish

    USMCfish USMC-FISH

    Location:
    Point Loma
    Name:
    Lee
    Boat:
    Tuna Can
    • Messages:
      (1,159)
    • Likes Received:
      (106)
    Ok, did compression check both cyclinders hitting @ 125 psi, so thats a good sign, I have the air mixture on the front of motor adjusted to so maybe it was getting to much fuel and fowling the plugs... going to re run it on monday and see hope I dont have to break out the paddle ;) thanks for all your help gents!
     
  16. captjeffjones

    captjeffjones Embellishment detector.

    Location:
    Huntington Beach, CA
    Name:
    Captain Jeff Jones
    Boat:
    Depends on which client....
    • Messages:
      (409)
    • Likes Received:
      (8)
    Tan gunk on lower plug? Sounds like water mixed with oil/fuel. Try this, trust me. Put a tiny smear of the tan gunk on your finger and wipe it on your tongue. If it tastes salty, you have saltwater getting into the block. Have a rag handy to wipe the tan gunk off your tongue. I'm dead serious. Used to do this when I worked for Cummins. My trainer taught me this trick and I was like "Nope, not doing it!" But it works.

    If indeed you have saltwater in the block, time is of the essence. It's corroding as you read this. Good luck.
     
  17. USMCfish

    USMCfish USMC-FISH

    Location:
    Point Loma
    Name:
    Lee
    Boat:
    Tuna Can
    • Messages:
      (1,159)
    • Likes Received:
      (106)
    I am not going to taste that stuff ;)... I just ran it for about 15 minutes in the tank and it wasnt as gunked up as before maybe this crap is burning out? Also with saltwater in the block how would it get inside there? Also running Champion plugs and I saw on a forum you can run NGK's with much less foulage... Any suggestions?
     
  18. 26grumpy

    26grumpy who hooked who

    Location:
    Anaheim Hills
    Name:
    Joe
    Boat:
    Freefrom Boats Club
    • Messages:
      (9,341)
    • Likes Received:
      (3,705)
    Make sure you have clean fuel in a verified clean tank. 90% of the time it's bad fuel that causes 2 stroke performance issues. It's ALWAYS best to run the carb(s) dry after use on those small outboards even if it just sits for a couple weeks.
     
  19. USMCfish

    USMCfish USMC-FISH

    Location:
    Point Loma
    Name:
    Lee
    Boat:
    Tuna Can
    • Messages:
      (1,159)
    • Likes Received:
      (106)
    One last ?, I am sorry to keep dragging this thread out and so long, I am running Mercury 2 stroke mix in my johnson could this be a problem or is 2 stroke oil 2 stroke oil?
     
  20. RASTA

    RASTA Newbie

    Location:
    riverside
    Name:
    richard
    Boat:
    boatless now
    • Messages:
      (525)
    • Likes Received:
      (0)
    your compression sounds good.i had this problem on my 70 hp evinrude,,wound up to be a bad coil wire.ignition will do funny things too.,,,by the way there is no reason for "valve work"on a 2 stroke engine.let me know if you get it lined out
     

Share This Page