Blown Piston

Discussion in 'Bubba's Outboards' started by TDawgNOk, Jun 7, 2006.

  1. TDawgNOk

    TDawgNOk Gathering Monitor (Instigator)

    Messages:
    3,365
    State:
    Tulsa, Oklahoma
    I recently *(as in last week)* had my boat in for a tune up.

    Tried using it this weekend and it didn't run right. I had to "slam" it into gear to get it to go forward. If I didn't "slam" it into gear, it would die upon attempting to ease it into gear.

    Called the shop, they said to let it warm up more. That didn't help any.

    I was able to pull a tube for a bit and it ran alright, but was a little rough. Ran out of gas in one tank and switched to the next. *(too rich mix 25:1 instead of 50:1)* Ran for a few more mins until all of the sudden I had to have the boat wide open to run at "no wake"

    My question, in your honest opinion, do you believe the piston was blown before I took it out, or, after? Could running too rich a mixture cause it?
     
  2. peewee williams

    peewee williams New Member

    Messages:
    3,111
    State:
    Pembroke,Georgia
    All 6 of my motors call for a 50-1 ratio with a 25-1 break in ratio.This spans 25 years.It never blew one of mine.Now! Different people have different meanings for "Blown Piston" What specifically happened to yours? peewee-williams
     

  3. TDawgNOk

    TDawgNOk Gathering Monitor (Instigator)

    Messages:
    3,365
    State:
    Tulsa, Oklahoma
    I will try and get a pic of it tonight. One thing I know, it was closing the gap on the spark plug and compression in that cylinder is down to 50 verses the other 2 at around 150-160
     
  4. Arkie55

    Arkie55 New Member

    Messages:
    669
    State:
    Mississippi
    Tdawg,
    I read your post twice. Some how I am missing the part about blowing a piston. I caught the part about running a littel rough and slamming the shifter in gear to keep it from dieing but missed blowing a piston.

    If it was mine, I would buy, rent, or borrow a compression gauge and test the compression on all cylinders. That will tell you a lot. You could have a bad ring. You could have a scored wall, you could have a carb out of adjustment, you could have a spark porblem, could be a timing issue, could be almost anything. More information please.
     
  5. Arkie55

    Arkie55 New Member

    Messages:
    669
    State:
    Mississippi
    Ok, you were posting while I was. Sounds like you did drop a cylinder.
     
  6. Bubbakat

    Bubbakat New Member

    Messages:
    4,532
    State:
    McMinnvill
    Running that mix would not have blown that cylinder. What would have is it dropping in and out firing because of a coil would have blown it. Without seeing it first hand it is hard to say what went wrong.
    If you had one carb putting fuel to the piston and another not putting fuel to a piston then you will loose a piston that way.
    Tony there are several things that can cause a piston to deteriorate. It could have been coked up and lost the carbon off the rings and scored the side wall or it could have blown a head gasket and done it.

    Lots of variable's in play here and it can't be diagnosed with out looking at the motor itself. Sorry
     
  7. TDawgNOk

    TDawgNOk Gathering Monitor (Instigator)

    Messages:
    3,365
    State:
    Tulsa, Oklahoma

    more information can be found here!
     
  8. Bobpaul

    Bobpaul New Member

    Messages:
    3,039
    State:
    Supply NC
    I read this thread and the other thread about your engine and it getting worked on then blowing a piston.

    Friday you said it had a problem getting into gear and dieing, but ran good eventually.

    Saturday, went tubing, because it ran well enough, you thought it was good enough to pull the kids.

    Quit running good.

    The leaking carb bowls could've caused it to die when going into gear, not blow a piston.

    Too rich of a mixture would fowl the plugs, not blow a piston.

    Pulling kids on a tube with an old Chrysler engine will blow a piston. You labored an old tired engine and are paying for it. It's a part of life you can't blame mechanics for. AKA, lesson learned, also known as experience.

    Sorry, no sugar coating. We all pay the price at one time or another.
     
  9. Bobpaul

    Bobpaul New Member

    Messages:
    3,039
    State:
    Supply NC
    Question; Which carb was leaking, and where was it leaking?
     
  10. TDawgNOk

    TDawgNOk Gathering Monitor (Instigator)

    Messages:
    3,365
    State:
    Tulsa, Oklahoma
    all three, more from the bottom two than the top one. They were leaking from the top of the bowls, down the sides of the carb bowls.

    My main reason for asking was to determine if the problem WAS caused by me this weekend, or, if it was a problem that should have been found at the mechanic's shop before they turned it over to me.

    Thank you for your thoughts Bobpaul.

    Next question, would a 50 hp rude be enough for a 14ft glassmaster tri-hul to pull the kids on a tube *(1 kid at a time)*
     
  11. Bubbakat

    Bubbakat New Member

    Messages:
    4,532
    State:
    McMinnvill
    Tony if you prop it right it will. If you are going to use a boat then by all means get you a tach for it so you can see what that engine is doing.
     
  12. Bobpaul

    Bobpaul New Member

    Messages:
    3,039
    State:
    Supply NC
    I was going to correct myself on the leaking carb. It could blow a piston if it leaked and caused that cylinder to run lean.

    Determining if the leak caused a lean or flooding condition on that cylinder is the problem.

    The point is it ran good, then didn't after the tubing. Coincidence, maybe.

    Like Bubba says, "Get a tach"