Results 1 to 7 of 7
  1. 04-01-2015, 04:22 PM #1
    hotpole!
    hotpole! is offline
    Member
    Join Date
    Jan 2015
    Location
    bluegrass region
    Posts
    17

    Evinrude, are black oily spark plugs a problem?

    I have purchased a 1993 deep V Sylvan with a 88hp V4 90 degree engine. I have ran it on muffs several times and on the water once. The engine will get the boat on plane, cruise @ 3500 rpm and go 4600 RPM at WOT trimmed up. I was having a problem with the engine coughing and quitting at idle but would start right back up. I found a fuel leak at the bulb and also at the engine fuel connector and now the engine will idle. The plugs are the correct Champion's and gapped at 30:1000. New set gets oily just like the old set. I did a decarb with OMC that screws onto the primer Schrader valve before hitting the water.
    Condition.
    When I pull the spark plugs they are black and oily looking. The boat has a large built in gas tank that is almost full. Probably 20 gallons gas/oil mix.
    Questions.
    Is there a way to check the gas/oil mixture so that I can adjust it if it is too rich in oil? I hope to keep from dumping all this fuel.
    Can I start adding fuel at say 100:1 and see if the condition gets better? Are there other reasons for this that I should be looking into? I have not had a compression test. Any and all thoughts welcomed.
    Carl
    Last edited by hotpole!; 04-01-2015 at 05:00 PM.
    Reply With Quote Reply With Quote
  2. 316jughead
    316jughead is offline
    Member
    Join Date
    Aug 2009
    Location
    Wichita KS
    Posts
    4,917
    #2 04-01-2015, 04:46 PM
    Does the motor smoke a lot? You may just have to run the boat and get the tank down to almost empty. Use good Evinrude oil.
    Reply With Quote Reply With Quote
  3. hotpole!
    hotpole! is offline
    Member
    Join Date
    Jan 2015
    Location
    bluegrass region
    Posts
    17
    #3 04-01-2015, 04:53 PM
    Smokes on the muffs. Have not noticed it when I had it on the lake.
    Reply With Quote Reply With Quote
  4. ChampioNman
    ChampioNman is offline
    SC Club Moderator ChampioNman's Avatar
    Join Date
    May 2004
    Location
    Crawfordville, FL/Lake Hartwell, SC
    Posts
    71,272
    #4 04-01-2015, 05:01 PM
    How long did you let the tuner stay in the motor? 8 hours is recommended. Also have you checked you cylinder head temps? And you mixing at 50:1 ratio?
    Reply With Quote Reply With Quote
  5. hotpole!
    hotpole! is offline
    Member
    Join Date
    Jan 2015
    Location
    bluegrass region
    Posts
    17
    #5 04-01-2015, 05:07 PM
    Quote Originally Posted by ChampioNman View Post
    How long did you let the tuner stay in the motor? 8 hours is recommended. Also have you checked you cylinder head temps? And you mixing at 50:1 ratio?
    I let the tuner stay in 14 hours.Cylinder head temps running 135-145*F on 42*F cold water, muffs. The fuel was in the tank when I purchased the boat.
    Reply With Quote Reply With Quote
  6. ChampioNman
    ChampioNman is offline
    SC Club Moderator ChampioNman's Avatar
    Join Date
    May 2004
    Location
    Crawfordville, FL/Lake Hartwell, SC
    Posts
    71,272
    #6 04-01-2015, 05:22 PM
    I'd burn the gas down then fill at 50:1 ratio.
    Reply With Quote Reply With Quote
  7. hotpole!
    hotpole! is offline
    Member
    Join Date
    Jan 2015
    Location
    bluegrass region
    Posts
    17
    #7 04-01-2015, 05:32 PM
    Quote Originally Posted by ChampioNman View Post
    I'd burn the gas down then fill at 50:1 ratio.
    Then that's what I will do.
    And I will post a follow up but it may be a couple of weeks.
    Reply With Quote Reply With Quote
« Previous Thread | Next Thread »