Atomic 4 Mechanic - Oakville, Ontario ???

  • Filter
  • Time
  • Show
Clear All
new posts
  • Aaz
    • May 2023
    • 4

    Atomic 4 Mechanic - Oakville, Ontario ???

    I’m looking for a reliable Atomic 4 mechanic in Oakville, Ontario.

    I noticed a steam rising out between manifold and exhaust. It looks similar to what is discussed here:

  • Dave Neptune
    Afourian MVP, Professor Emeritus
    • Jan 2007
    • 5099

    First welcome to the MMI Forum.

    Looking for an A-4 mechanic is often asked and almost never answered. Most of these old A-4's are rusted up and somewhat difficult for a mechanic as they would prefer working an a newer clean engine, it's just a fact.

    Those of us here have learned to maintain and fix our A-4's through this forum and our gracious host, Don. MMI and Indigo are about the only suppliers of anything A-4 and MMI has most everything even new castings.

    If you find someone treat them well and do post them up here for anyone else in your area.

    Good luck.

    Dave Neptune


    • ndutton
      Afourian MVP
      • May 2009
      • 9777

      You're going about it the right way Aaz, get referrals. It's less painful and expensive than finding you hired the wrong guy the hard way.

      I was recently involved in helping an A4 owner who paid a professional mechanic over $500 for an oil change and carburetor rebuild which did not resolve the reason he was hired - the engine would quit when brought down to idle. As a quick diagnosis we swapped out the carburetor with a known-good test carb and the engine ran perfectly. Upon disassembly of the old carburetor we found the gasket between the body halves was broken in three places and glued back together with Permatex, there was no evidence of any replacement parts (float valve in particular) and the top half was slightly warped. A proper carb rebuild restored the engine to perfect running condition.

      So exactly what was the $500+ for? An expensive lesson was about all.
      1977 Catalina 30
      San Pedro, California
      prior boats 1987 Westsail 32, 1970 Catalina 22
      Had my hands in a few others


      • TimBSmith
        Afourian MVP
        • Aug 2020
        • 161


        The day before I was due to launch in 2021 I noticed steam and dripping water from the water injection port on my riser. This is something you cannot "unsee" and that you do not want to launch with pending 45 minutes motoring to a mooring field. You may want an mechanic, but do you really need one? This group held my hand through exhaust system diagnosis, rebuild of riser, replacement of marine exhaust hose. Some of the work that even more modestly skilled newbies can handle, and that help them understand the function of their motors. If time is the issue, I understand seeking a mechanic. Short of that, use this as an invitation to grow into the mechanic your motor needs you to be. And that you will want to be if you are, for example, off shore and some kelp plugs your raw water intake causing over-heating. Carry on. Good luck.
        Tim Smith
        Pearson 30
        1974, Number 572
        Boston, MA USA


        • Aaz
          • May 2023
          • 4

          Thank you to everyone for the comments,

          Here is how the problem looks like. The yellow circle indicates where a stream is rising from

          Does it required immediate attention? What should I start with?
          Attached Files


          • Bryan Janeway
            Senior Member
            • Jun 2017
            • 22

            Hello Aaz,

            Welcome to the site!! I’m not a mechanic but have owned my Atomic 4, Northern 29 for 8 years. I have pretty much messed with every part of my motor due to all kinds of issues. Well mostly overheating. But with problems solved, mine continues to be a well used and happy motor… Regardless… we are fortunate to be in fresh water and your manifold is likely intact and not rusted out. Provided you did a proper winter prep and didn’t crack your manifold you likely just need some sealant on your fittings and perhaps a new exhaust gasket. There shouldn’t be any water inside the exhaust at that point.. the water is added prior to the lift. You might want to check the “inline cooling water exhaust entry fitting” for cracks and see if water isn’t soaking into the exhaust wrap causing it to steam off when the temp comes up. Also to check for manifold cracks undo the exhaust fitting at the end of the manifold. Water should not leak out. Also pull both cooling hoses off the top of the manifold, cover one end with your thumb and blow hard into the other. You shouldn’t hear any air escaping, it should hold pressure.

            I redid my manifold with indigos thermostat mod. When rebuilding I used the hi temp permatex pipe dope. That seems to keep little leaks from occurring. If you aren’t comfortable tearing into it I’m in KW, not far from you. Im home from work early Tuesday and free most of the week. PM me I can take a look. The only issue I have is my boat tools and spare parts are on my boat in Midland. So if there is anything major to do you would need a reasonably good tool kit.

            Let me know,