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wbgent 04-06-2003 02:35 PM

Atomic 4 - Water in Cylinders!!!
After sitting idle for about 2 months, I tried to start my engine. I cranked too long and the water from my raw water cooling system apparently backed up. There was water spitting out of the flame arrestor when I cranked the engine and there is water in the carb. I pulled the plugs, and there is water in the cylinders. Not pooling, but it''s definitely water. Now, I think my immediate concern should be to preserve the cylinders and try and plecude any more damage - before I troubleshoot why the engine wouldn''t start. Right? Here''s what I''m doing:

1. Put a couple of tablespoons of Marvel Mystery Oil in each cylinder. I will let that soak while:

2. I drain the gas tank and fuel lines. Initial investigation revealed no water in the fuel filter resevoir, but the fuel didn''t smell as strong as it should have.

3. Crank the engine w/ the plugs out to blow the MMO and any residual water out of the cylinders.

4. Replace new plugs.

5. Fire the engine while spraying a squirt of starter fluid into the carb and the intake shut. If it starts, then open intake.

Am I missing anything here? Does the water spitting out of the flame arrestor indicate a bad head gasket/ head leak?? HELP!!!


pirateofcapeann 04-06-2003 04:40 PM

Atomic 4 - Water in Cylinders!!!
Yup, well, that''s about as classic a sign of a blown head gasket as there ever was! The reason it wouldn''t start is because you weren''t getting any compression. This could be a symptom of other problems too like a stuck valve, a cracked head or block or a broken timing chain even, unlikely but possible especially if you live in a northern climate and didn''t winterize the engine. The first step is to do a compression check. You''ve done well to pour some mystery oil in the cylinders. Don''t be bashful with it and turn the engine over by hand a couple of times after you pour it in.


wbgent 04-06-2003 06:23 PM

Atomic 4 - Water in Cylinders!!!
Thanks a million! I live in Hawaii - no winterization! I guess I''ve got to pull the head! Anything to watch out for there?


pirateofcapeann 04-07-2003 08:34 AM

Atomic 4 - Water in Cylinders!!!
I strongly recommend you source out a shop manual if you''re planning to do the job yourself. That will answer all of the questions you''ll have on how to go about the job and tools required as well as bolt torque, patterns and the like. It will also keep you from getting into too much trouble. Doing this job yourself is a great idea, as it will give you some very good experience and knowledge about your motor, which may come in handy someday away from the dock!


Irwin32 04-07-2003 08:01 PM

Atomic 4 - Water in Cylinders!!!
Do not assume you have blown a head gasket. Cranking the A4 excessively w/o starting can result in water getting into the cylinders. You did the right thing by getting the water out and getting MMO into the cylinders. Hopefully you cranked it over to get the MMO to your rings.

Run a compression check.

If your engine was running fine the last time before you shut it down I am going to bet is is still OK. Head gaskets don''t blow just sitting around and waiting.

After you get it going and check the compression, keep your eye on things. Check the oil to look for signs of water. I am putting my money on your engine is OK and you just cranked it too long.

I think what happens is that as you you crank, exhaust water backs up because the engine is not kicking it out with enough force and it ends up backing into your cylinders.

One can install a drain valve at a low point in the exhaust system downstream from where the water enters. When the engine is being stubborn, that valve can be opened to prevent the exhaust system from filling up with water.

RobGallagher 04-07-2003 10:02 PM

Atomic 4 - Water in Cylinders!!!

There are guys on this list that know everything there is to know about the A-4

Good Luck

ncstatesailor 01-17-2010 06:05 PM

I realize this is an old forum.. but I have had the exact same problem. I left the sea valve open for a couple weeks and then started up the engine after a couple tries. We motored about 200yds and then the engine all of a sudden sounded like it had no power.. and the throttle did very little. We just made it back to the dock before it died.

Upon inspection, there was water in the carb and so we followed all the steps here about putting MMO in the cylinders and cranking her a few times... draining the carb.. etc...

But after the carb was dry and everything was put back together... we cranked the engine... with no luck.. and then saw that water had filled up the carb once again.

Anyone have any ideas as to why the carb keeps filling up with water after i try to start the engine? (Atomic Four - raw water cooled)


Faster 01-17-2010 06:43 PM

As you crank the engine, if the water intake is open the water pump is moving water. If the engine does not fire, the water is not "blown" out of the muffler and out the exhaust. it simply fills the exhaust system, and eventually the water level is high enough in the system to run back into the engine through any open exhaust valve. The intake should be shut if your expect to crank more than a a few seconds to start, then quickly opened only once the engine is running.

That's one possibility, anyhow, as is a blown headgasket in which case water can get directly into the cylinder from the water jacket. As indicated earlier in this thread, lack of compression will make starting difficult.

SEMIJim 01-17-2010 07:19 PM

What Faster said.

In a typical A4 installation you don't want to crank for more than about 30-45 seconds with the raw water intake open and the engine not firing. That's a cumulative number, by the way. If our A4 does not start after about 30 seconds of cranking, the raw water intake gets closed until she fires up.


ncstatesailor 01-17-2010 08:04 PM

We have the raw water valve intake closed.. and am still getting water in the carb. The water looks oily/milky... what could this mean? After putting the MMO in the cylinders... we saw it drain a little bit into the carb...

we fired the engine w/ the spark plugs out 3 or 4 times.... should we fire it w/o the plugs more to drain even more water out of the cylinders, or do you think that was enough?

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