Posted by Ross (220.127.116.11) on July 05, 2004 at 01:06:05:
In Reply to: Engine flush posted by Jim on 16:17:16 07/02/04:
I found the site where I found the procedure for flushing the Atomic 4, I think I ran the pump steady for 3 hours. I think I added 1 gallon of water to the Marsolve, but can't remember for sure. Also, I have a barrel valve before the thermostat housing, to manually control the coolant going thru the bypass. The thermostat has been removed. This is a common modification, your engine may have it. I have since installed fresh water cooling and have added a filter to raw water inlet going to the raw water pump. Works good I can adjust temperature by adjusting barrel valve. No more high readings on temperature gauge. Here's the site address:
It's the one that says flushing out the Atomic 4 cooling system.
1. Close the seacock at the seawater coolant inlet.
2 Remove the thermostat. To remove the thermostat, remove the two nuts holding down the thermostat housing. Lift up the housing and remove the thermostat then reinstall the housing.
3. Pinch off the by-pass hose - between the water-jacket plate and the inlet to thermostat housing. This will force the acid flush to clean the entire cooling system.
4. Disconnect the coolant line from the output side of the engine water pump. Connect a 3' section of hose to this coolant line using a barbed hose connector. Attach the other end of this hose to the output side of the drill pump. Attach another 3' section of hose to the other side of the drill pump. This hose will draw the acid solution out of the bucket.
5. Disconnect the coolant line from the coolant fitting on the exhaust manifold. Attach a 4' section of hose to the coolant fitting on the exhaust manifold. This hose will return the mild acid solution back into the bucket.
6. Put the acid crystals into the bucket. Pour a gallon of hot water into the bucket and stir to dissolve the crystals. Add 2 more gallons of water.
7. Start the drill pump and run for about 5 minutes. Its amazing how much junk comes out in the first few minutes of this flushing process. Run the drill pump for about 30 seconds every 5 minutes for the next 2-3 hours.
8. While the mild acid solution is dissolving the deposits, disassemble the thermostat and clean it thoroughly. Then reassemble it.
9. After circulating the acid through the engine, properly dispose of the solution.
10. Refill the bucket with clean water and flush out the remaining acid solution. Dispose of the water and refill the bucket again with clean water. Add a small box of baking soda to the bucket to neutralize the acid and flush the engine for another 10 minutes.
11. Reinstall the thermostat using a new gasket so the housing doesn't leak.
12. Reinstall and clamp the coolant hoses to the engine water pump and coolant fitting on the exhaust manifold.
13. Open the seacock to the cooling system and start the engine to test for leaks and take her out for test.
1. 5 gallon bucket
2. inexpensive drill driven pump
3. 10' of 1/2" ID hose,
4. 1/2" barbed PVC hose connector,
5. threaded/barbed fittings for the drill driven pump
6. 2 lbs. oxalic acid crystals (available in hardware stores in crystalline form)
7. Baking soda
8. hand tools
9. New thermostat gasket