How bad is this piston?

Discussion in 'Bubba's Outboards' started by tbull, Dec 10, 2008.

  1. tbull

    tbull New Member

    Messages:
    3,318
    State:
    SW Ohio
    Well I need to insert a helicoil on one of my cylinders, so I removed the head, and noticed the piston was kind of chewed up. Also the cylinder head is kind of chewed up in the same spot. Also got a good look at the coils and one is cracked. Still fires, dont know if this will be an issue in the near future or not. Take a look at these pics, and info would be appreciated. The piston above this one looks immaculate, I think someone may have opened up the crankcase and replaced that in the not so distant past. Thanks guys.:embarassed:
     

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  2. catfishcrazy256

    catfishcrazy256 New Member

    Messages:
    2,648
    State:
    Indiana
    Should be fine, I would use it .
     

  3. RRRKKK

    RRRKKK New Member

    Messages:
    68
    State:
    Quincy IL
    Do you have a compression reading? That will tell you a lot. If you don't and its running allright I would helicoil it and put it back together.
     
  4. tbull

    tbull New Member

    Messages:
    3,318
    State:
    SW Ohio
    The last compression reading before this helicoil problem was well over 100 for each cylinder, i will do another once reassembled. I was thinking the same thing though, It ran fine before this problem.
     
  5. Sonny Kemp

    Sonny Kemp New Member

    Messages:
    146
    State:
    Tn
    Travis Id say you have gotten good advice.I would put it back together and check compression.Those marks are probably what got in there from previous threads.If a piece of it didnt go down the edge and seize a ring being on the top like that wont hurt anything.Comp check will show if it did.
     
  6. tbull

    tbull New Member

    Messages:
    3,318
    State:
    SW Ohio
    The cylinders wall were still as smooth as can be which is a good thing, still would like to know where those pieces went because something caused that...
     
  7. Sonny Kemp

    Sonny Kemp New Member

    Messages:
    146
    State:
    Tn
    Did it have a helicoil already in it or are you putting in for first time time?If you are replacing it,it is probably the tang off the bottom of the original helicoil somebody didnt get out when it was installed or part of it.If you are putting one in for first time it is probably some of the original stripped threads.Either way the trash from it probably went out the exhaust.
     
  8. tbull

    tbull New Member

    Messages:
    3,318
    State:
    SW Ohio
    Pretty sure this is the first Helicoil
     
  9. Bubbakat

    Bubbakat New Member

    Messages:
    4,532
    State:
    McMinnvill
    Don't use a heli coil, Use what is called a steel insert and when putting it in lock tite it into place with some lock tite. Make sure you don't get any on the threads of the plug because you won't get it out.Then you don't have the problem of a soft coil falling into the cylinder like that. As for running it I would have to look at it personally to really give you a straight answer because it matters how deep the gouges are and how far they run down the wall. If you have good compression then I would say it is safe to run. Before replacing that cover be sure to check the head for warpage. The coil that is cracked I would replace.