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  #1   IP: 208.252.62.130
Old 07-15-2005, 09:57 AM
seators
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Much much water in Atomic 4

Two days ago I was cranking over the Atomic 4 in my 1976 Tartan 30. After considerable time cranking (about 30 seconds) the engine made a loud pssst sound similar to the sound of an automotive carbourator sucking for air. Upon inspection I noted that there was seawater flowing out from beneath the flame arrestor for the carb. In addition, removal of the #4 plug revealed water in the piston. I also noted a spray of water that pushed out of the water pump side of the engine and hit the adjacent berth (about 1.5 ft away).

Disassembly of the water intake seemed to show that water was coming IN just fine.

My questions are:

1. What could be going wrong?
2. What steps should be taken to "clear" the engine once the problem is resolved?

Any help/ideas on this would be great.

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  #2   IP: 38.118.52.61
Old 07-15-2005, 09:08 PM
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Don Moyer Don Moyer is offline
 
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Seators,

Below is a technical note we prepared on the subject of water getting into the cylinders and out through the carburetor. My best guess is that the water in your engine backed up from the exhaust system as you cranked the engine trying to start it.

About halfway through the note you'll come to the section on how to get rid of the water.

CAUSES OF WATER GETTING INTO CYLINDERS (and running out of the intake throat of the carburetor):

1) The most common way for water to get into the cylinders of an Atomic 4 is for cooling water to back up within the exhaust system by over-cranking the engine with the raw water through-hull open. Without the engine running and producing exhaust pressure to move the cooling water out through the exhaust system, water will continue to collect within the system until it reaches a level that enables it to flow back into the manifold. From there, the water has a direct pathway back into the combustion chambers.

2) Sometimes, problems within the exhaust system will only manifest after sailing. If water intrusion only occurs after sailing, try closing the raw water through-hull fitting while sailing, and see if the problem goes away. If it does, you'll have to troubleshoot the exhaust system, or keep your through-hull closed whenever you're sailing.

3) Raw water can enter and flood the exhaust system through an open (or leaking) through-hull while sailing, or setting in a slip. Since sail boat engines are almost always below the theoretical water line, it is necessary to loop the raw water hose from the engine (or heat exchanger) above the water line prior to connecting it to the exhaust fitting to prevent hydrostatic pressure from outside flooding the exhaust system. The top of this loop must have an anti-siphon valve installed to prevent water from siphoning into the exhaust system and flooding back into the exhaust manifold.

4) Leaky head gaskets can result in water getting into one or more cylinders. When head gaskets fail, there is usually evidence of poor running or hard starting caused by loss of compression and/or water fouling the spark plugs.

5) Holes or cracks in the head, manifold, or deck of the block can also result in water entering the cylinders. If these problems become suspect, proceed to step (4) below.

WHAT TO DO IF WATER IS DISCOVERED IN THE CYLINDERS (OR RUNNING OUT OF THE INTAKE THROAT OF THE CARBURETOR):

1) If water is discovered in combustion chambers, perform the following precautionary steps as soon as possible:

a. Close the raw water through-hull valve.

b. Remove all spark plugs and squirt lots (5 or 6 squirts) of Marvel Mystery Oil (MMO) in each cylinder to prevent pistons from seizing. Try to aim the MMO away from the manifold side of the engine, toward the cylinders.

c. Turn the engine over with the starter until most of the evidence of water is gone from the combustion chambers.

d. If water was seen to run out of the intake throat of the carburetor, remove the main passage plug (the plug that you would remove to remove the main jet), and allow all the fuel and water to run out of the carburetor.

2) Dry (or replace) the spark plugs, and try to start the engine. If the engine starts, open the raw water through-hull.

3) If the engine starts and runs satisfactorily, check for water in the crankcase. If water is present, change the oil at least three times, running the engine just long enough between changes to mix up the water and oil, to maximize the amount of water that comes out with each oil change.

4) If engine will not start, or If the engine falters after opening the through-hull, and water is seen to be reentering the cylinders, shut off the engine, re-close the raw water through-hull and proceed to check the following (listed in order of likelihood of occurrence):

a. Perform a compression check. If weak compression is discovered in two adjacent cylinders, a failed head gasket is probably the cause of the water entering into one or more combustion chambers.

b. If compression is weak on only one cylinder, check to see if air can be heard to be escaping into the water jacket of the head during the compression check. A sound of escaping air during the compression check would indicate a small hole in the combustion chamber of the head.

NOTE: Removal of the thermostat housing would make it easier to hear a compression leak into the water jacket of the head.

c. Remove the hoses from both fittings on the manifold and blow into one fitting while holding a finger over the other. If the manifold will not hold air, a leak in the water jacket is indicated, and the manifold will have to be replaced.

d. If the head, head gasket, and manifold appear sound, a crack in the cooling jacket of the block, would be suspect. In this case, it will be necessary to pressure check the block. The easiest way to pressure test the block (without removing the head) is to first plug the outlet of the thermostat housing. Then remove the hose from the outlet of the water pump, and install a Schrader valve in the end of the hose, so that a standard bicycle tire pump with a built in pressure gauge can be used for the test. A Schrader valve is the standard valve used on automobiles, and they are available at any auto parts store. The block should be able to hold 20 psi for an hour or more without a noticeable drop in pressure.

NOTE: It would be preferable to remove the manifold for the above pressure test so that the valve ports can be inspected during the test.

e. If pressure decays rapidly, look for water leaking out though one or more exhaust or intake ports. If water is leaking from an intake or exhaust port, it may be impossible to see exactly where the water is originating , but a defective block would definitely be indicated and the block would have be removed from the engine and taken to a machine shop for evaluation.

Don

Last edited by Don Moyer; 07-15-2005 at 09:10 PM.
  #3   IP: 66.30.32.75
Old 07-16-2005, 09:53 PM
seators seators is offline
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Thank you!

I cannot thank you enough for this information. I'll be sure to let you know how it turns out...
  #4   IP: 68.99.168.186
Old 08-10-2006, 03:31 PM
RISAIL
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Tartan 30

seators,
I also have a Tartan 30. See my reply to John Feingold's post under the Troubleshooting heading. In the past 15 months I have installed a remanufactured Atomic Four and a new fuel tank. I also installed a fresh water cooling system (at over $500) SPECIFICALLY to avoid these kinds of problems. I have met and/or communiated with a number of wonderfully friendly people who are only too happy when I read my credit card number to them.
I have now had two summer vacations cut short because of an Atomic Four. I think it's time we realized what many others did 25 years ago: these engines are dinosaurs and it's time to move on.

Joe Walkden
RISAIL@aol.com
October Moon
Tartan 30 #572
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