Piston damage from blown head gasket

OLD BAY, Jul 5, 2017
    • Lawai'a
      That's bad. What motor and hours did that happen.
    • OLD BAY
      1993 Johnson 88 SPL. I don't know the hours, but probably less than average for that age engine. I'm going to guess less than 1000. It was stored in a barn for 10 years then the next owner used it at his summer home for 10-ish years. Then I got it. We've likely put 500 hours on it in the four years we've had it.
    • HappyHour
      I just had to rebuild a engine cause if a cracked cylinder head. Cracked between the intake and exhaust valves on all 6 cylinders. Looked kinda similar to that, but the damage was more in the center of the pistons.
    • Lawai'a
      @OLD BAY are ya junking it or rebuilding
    • OLD BAY
      Sorry to hear about yours HappyHour, was it a coolant problem?

      Lawai'a, I'm rebuilding it. If I can get another 24 years out of it for the lower cost of rebuilding (compared to new or even newer but still used) that's a good enough deal for me.
      Lawai'a likes this.
    • leaky
      Haha this is funny - I saw the picture pop up on the site and thought "that's ain't no inboard it's a Johnson crossflow". I know a bit about these - to do it really nice it's probably $1200 in parts and machining by the time you get done with bearings gaskets and all the little parts but it can workout real good. If the cylinders are all OK and it's just a cracked up piston you can deglaze, pop a piston in it, and use all the original parts but it's alot of work for what you get that way, not much less work than conducting a real rebuild just cheaper.

      The thing that sucks about these (all OMC's and Bombardiers from my understanding) is aligning rod caps, can be a real bitch, can make it so you end up needing an extra rod or two because some are a real pain or impossible to align. Check Ebay to see if anyone has new rods hanging around cheap, they are easier to align when they have never been used.

      For machining I highly recommend shipping it if needed to get it to a shop who specializes in outboards - a very savvy old school machinist will do a good job since they understand all engines but most specialize in diesels and have a hard time with these blocks. Make sure no matter who does it that they measure the pistons for clearance and bore based on clearance, not based on ".020 over" since often aftermarket pistons are a touch on the small side, which results in kinda a loose product when you are done if the machinist doesn't pay attention.

      Lawai'a and OLD BAY like this.
    • OLD BAY
      Thanks Jon. I started pulling it apart myself but I'm running out of summer, so a local guy here in Annapolis that knows these engines inside and out is looking at it. He thinks the cylinders are good and can get it back to me in a week or two. I'm going to have him do a total rebuild, since I'm having it apart anyway.

      I enjoy reading about your 32' Holland build thread.
      Lawai'a likes this.
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