Pro xs,water in air rail

[Rip Bass]

200 pro xs,serial # 1B864384. Last Saturday it developed a noticeable miss at idle that went away at about 2k rpm while planing. I loaded up and came home, checked the plugs. They all looked good,nice brown color,none were steam cleaned. Later,I pressed the air schrader valve and saw what I thought was fuel so I checked the tracker valve diaphragm,no tears in it. Then I checked the air and fuel regulator diaphragms,no tears in them but the air regulator diaphragm was covered with a yellowish sludge, it looked like fuel and water mixed. I removed the air line from the stbd rail and it has water in it. I removed the head and reed plate from the compressor to check for bad o-rings,none were broken but there was a rough spot on one about 1/4” long,looked like maybe it had been leaking. There was no water in the compressor cylinder,no crack in the head that I could see,no lateral or vertical movement in the compressor crankshaft. So,is there any where else that the water could have been coming from,other than the compressor? I will be sending the rails off to be cleaned. Any help is greatly appreciated,thanks.

[lpugh]

High humidity and condensation, should be a very small amount though

[Savage]

I think you tore alot of stuff apart for no real definitive reason......

Perform a spark test as the problem is occurring.

Test air and fuel pressures with dual liquid filled gauges.

Get accurate data before disassembling components alot of times a second problem is introduced unintentionally

[Rip Bass]

Thanks for the replies gentlemen. I’m sure I have a problem somewhere,this was more than a few drops of condensation,water ran out of the air line when I removed it from the upper stbd rail and the entire air diaphragm was covered with the yellowish sludge. I have a cell phone pic of it but don’t know how to post. I can text it to your phone though. Thanks again.

[lpugh]

It would be wise to put it back together and:

Visual inspection of ignition and fuel system
Mist the coils and wires down to check for secondary leaks, or do as I do and run you hands over everything, if you get bit you have found a problem that needs repair
Perform a spark test first, timing light for quick test, if good, then a kv test to check available voltage from coils
continuity test of plug wires
Fuel and air pressures test including leak down rates
Drain the VST into a clear container to check for water, a very small amount could be acceptable

Compression test

Now you will be ready to determine a path to follow, report back with you test results at this point, Actual test results, not tested good or ok

I would not spend any money or make any repairs until all of the above is checked

[lpugh]

Thanks for the replies gentlemen. I’m sure I have a problem somewhere,this was more than a few drops of condensation,water ran out of the air line when I removed it from the upper stbd rail and the entire air diaphragm was covered with the yellowish sludge. I have a cell phone pic of it but don’t know how to post. I can text it to your phone though. Thanks again.

916 813 0321

[Rip Bass]

Lpugh,I did drain the vst,no water there,none. I did perform a cold compression test as I was leary of running this engine. Compression was from 105-117,again cold. Thank you,I will send you a picture.

[JOE54]

port side rail is water cooled, most likely place is compressor leaking , might try o ring on head, is this salt water mtr ???

[lpugh]

^^^^^^^^ and,
Looks like oil mixed with water, somewhat like we see in autos with water in the oil (yellow whipped cream). Check for under cowl water leaks that could be ingested by the compressor
Check the compressor intake hose for proper locations and connection

[Rip Bass]

No sign of under cowl water leak that I can see,this is a freshwater engine also.I pulled the head off the compressor and there is a 1/4” long rough spot on one O ring,I think that is my leak. Left a message with Don at European marine yesterday but not heard back and called this morning,no answer except recording. Are they open this week? Mr.Pugh,do you agree that is an abnormal amount of moisture? Just for some background, engine was running perfectly all morning. I sat it down after a run to fish and it immediately starting skipping. I was ten miles from the ramp so I ran slowly back,it didn’t seem to be missing above about 1500-2000 rpm. Again,thank you.

[lpugh]

No sign of under cowl water leak that I can see,this is a freshwater engine also.I pulled the head off the compressor and there is a 1/4” long rough spot on one O ring,I think that is my leak. Left a message with Don at European marine yesterday but not heard back and called this morning,no answer except recording. Are they open this week? Mr.Pugh,do you agree that is an abnormal amount of moisture? Just for some background, engine was running perfectly all morning. I sat it down after a run to fish and it immediately starting skipping. I was ten miles from the ramp so I ran slowly back,it didn’t seem to be missing above about 1500-2000 rpm. Again,thank you.

I do agree and I am inclined to think this is compressor problem considering the oil mixed with the water, I would check the oil drain for the compressor for this as well. If water found its way into the compressor crankcase there may be a mess
Keep in mind I am not a Mercury tech, just an above average auto tech with some experience with mercs, Others on here deal with them daily

[Rip Bass]

I should have some compressor seals coming from European soon,talked to them today. Getting the rails cleaned now. I don’t see any sign of water in/on any of the injectors,is that possible?

[lpugh]

My biggest concern is how you got enough oil in the the air system as to make that much whipped cream. Makes me wonder if the compresor rings and piston are in good shape or water is in the crankcase whipping up the foam and it being pushed past the rings,
What do you think Joe?

IMG_0359.jpg

[lpugh]

Thanks for the replies gentlemen. I’m sure I have a problem somewhere,this was more than a few drops of condensation,water ran out of the air line when I removed it from the upper stbd rail and the entire air diaphragm was covered with the yellowish sludge. I have a cell phone pic of it but don’t know how to post. I can text it to your phone though. Thanks again.

I emailed it to myself, then resized it. Then used the insert image icon to load it on here

[Rip Bass]

I do pre-mix my fuel at a measured 150-1 with premium plus but that shouldn’t affect the air side. I don’t know about the compressor rings and piston but the cylinder looks good. Hash marks are still visible with very little sign of wear. None of the diaphragms had a tear and they are all the newer purple type. Once I get it back together, I will get the fuel and air pressures. Maybe should have done those first,but once I saw the water,I didn’t want to run it anymore.The spark is good and constant at idle,I did check that before disassembly.I might be wrong but I still think the compressor is the root of my problems but I’m open to suggestions. Thank you Mr. Pugh,I appreciate your time.

[lpugh]

Hey I learn from this also. Did you pull the drain hose off the compressor to check for foam in them? Just thinking out load but I can see how water could get past the rings and foam the oil in the crankcase. Then the rings could not wipe it off the cylinder walls properly thus it gets passed on

[Rip Bass]

I haven’t checked the compressor filters yet but I will tomorrow.I will probably replace them anyway.I’m assuming by drain hose that you mean the oil return line?Is it worth it to disassemble the compressor to check for sludge or water in it? The belt and head is off now, not all that much more trouble. How could water get into the crankcase other than a leaking head o- ring? When I was checking for spark,I had it running on a water hose with the cowl off,I’m sure there wasn’t a water leak anywhere.

[lpugh]

If water enters the compression chamber it can go past the rings as a vapor or liquid, foam up the oil, the rings lose control and oil can be passed back up in the compressor. Not saying this is happening, just that it could be. If foamed up it would be very hard for excess oil to drain from the compressor in a normal manner resulting far more than normal in the compressor

[Rip Bass]

That makes sense,I’ll check it tomorrow. Thanks.

[Rip Bass]

Waiting on parts,I’ll keep you posted.