four-cycle outboard motor WTF question

Discussion in 'Off Topic' started by Chris Crew, Jan 16, 2010.

  1. Chris Crew

    Chris Crew Member

    It has been cold here in the south lately, like really, really cold. I went out one saturday a few weeks ago and gave the starter on my Briggs and Stratton 5 hp outboard a tug and it seemed frozen solid. Today when it became more seasonably warm, I tried again to no avail, so I took the plug out and shot some lubricant into the hole and gave a little tug---she turned over just fine, but shot about a two-ounce blob of motor oil out of the hole.

    After I cleared the cylinder, I put the plug back in and gave another tug, and the compression was almost too much to overcome. I took the plug back out and found another big shot of oil in the cylinder.

    Now, during a rainy spell, the bows under the tarp gave way and the extra weight of the water propped the boat up with the trailer so that the motor was at an angle with the carb lower than the front of the motor. That's the only thing different about how this very reliable engine has been stored and used for years.

    So, WTF???? Any ideas? Is this motor wrecked?

  2. arceeguy

    arceeguy Active Member

    If the engine was tilted far enough, crankcase oil seeped past the rings and filled the cylinder causing it to "hydrolock" when you tried to start it. Your carb may have dumped raw fuel into the crankcase too, diluting the oil and raising the oil level. Is the oil thin and does it smell like gasoline?

    With the plug removed, pull the starter a bunch of times to blow out the oil. Check the crankcase oil level, and top off if necessary, replace the plug with a fresh one and give it a try.
  3. Esteban

    Esteban Active Member

    I have seen these engines have the above problem. Water gets into the fuel & causes this,, or tilting causes the oil to get into the cylinder. With these motors it seems like they absolutely must have fresh fuel.
  4. mikem

    mikem Member

    I think arceeguy has the right diagnosis here. I'd only add that it might be best to drain the crank case and refill to proper level with new, undiluted oil. A new spark plug and a new tank of gas might assure a fast start up too.
    Last edited: Jan 16, 2010
  5. professor

    professor Active Member

    Guys with the carb lower than the engine, fuel would go OUT of it , not in. At any rate, it is an oil issue and easy to remedy.
  6. Chris Crew

    Chris Crew Member

    Thanks, gents.
  7. eastwoodo4

    eastwoodo4 Member

    that things trashed!you better sell it to me for 20 bucks so its not a total loss.

    just the kinda guy i am.dont mention it!
  8. Chris Crew

    Chris Crew Member

    no problem, Eastwood---just make sure you pay with a twenty dollar gold piece . . .