Flushing Your Classic Boat Engine In The Driveway, Not Down The Toilet!

OK cramming a 1000 lb flat head down the stinker may be a tough thing to do, but if you don’t keep it cleaned out the right way you may think that’s your only option. I have learned this the hard way. I always knew this was the process, but short cuts and thinking it only needs to be done from time to time is a were the mistake happens. Here are some simple rules I follow after each use.

1. Hook up a small open hose to the water pump. A dead hose. Now you may not have such a fitting on your water pump. Any hardware store has the fittings and lever. It’s a 1 hr job, that will save you in the end if you live near salt water.2. Fill up a 5 gallon bucket with water from a real hose from a tap.

3. DO NOT HOOK UP THE WATER HOSE TO THE ENGINE. It will blow the weak, bad designed seals in the water pump, and thus put water in your oil. This is a pain in the ass if that happens. You will not be sure if its a head gasket, cracked block. or $ 400 water pump. NO KIDDING!

4. Put the dead hose from the engine to the bucket. NO TAP. I use a clear type hose. I can see what happening, You can also feel the suction from your pump in the bucket. Kinda cool.
5.. After its all hooked up. Start the motor and run it till you feel that its all flushed through. MAKE SURE THAT THE WATER IN THE BUCKET DOES NOT NOT GO OUT. Or the hoses. That happens. It should be OK if you idle. Stop the engine.

6. Disconnect and cap the hose fitting on the engine and shift the lever down, letting all the water drain. This way you won’t forget when you start it up the next time. Another mistake I have made on a previous boat.

This ritual may seem like a pain. But it will save you a manifold and countless hours of worry if you do it. I know, I have made everyone of the mistakes. Doh!

2 replies
  1. Matt
    Matt says:

    You can buy a “fake-a-lake” from any marine store that makes this way easier. It’s basically a plunger with a hose inlet that props up against your raw water intake under the boat. Takes, maybe 2 minutes to set up.

  2. woody boater
    woody boater says:

    Dang, but what about all the hard work and extra effort. Dang dang dang.. I am still old school I suppose. From what I can tell though, its still a hose pushing. Not as much as directly but after the hell I have been though I aint taking no chances.

Comments are closed.