Mystery still not solved

[speedwrench]

Still getting water into #1 cylinder when running, 1996 75 Force. <br /> Head has been cut and new head gasket. Block straight on head and exhaust. New exhaust plate and gaskets, both base gaskets replaced. <br /> Cleaned all carbon out of exhaust ports and cleaned all water jackets. No sign of crack or where the water is getting into cylinder from.<br /> Pulled intake transfer port covers. #1 was dirty with brown carbon & water blown back from cylinder (I guess). #2 & 3 clean. Compression 132-131-133. Low hours on engine, has not been overheated and never in salt water. FNG on outboards, lots of experience on 4 cycle and diesels. What am I overlooking??? Is there some way water can get in on intake side??? Manual not real clear. I'm running out of ideas.<br />Engine is on wife's pontoon boat, I'm about to get in DS if it doesn't get fixed soon.

 

[12Footer]

Re: Mystery still not solved

Honestly, I can't think of anytihng else that would allow water into the jug , other than what you have addressed allready. These engines have a problem with exaust port plates warping easily, and therefore, it's usually where the problem is found. Try removing it, and getting some "right Stuff" gasket maker. It comes in a small can the looks like a black cheeze-whizz can, and is about 8 buks at the auto parts store. Re-set the exaust port plate and manifold gaskets using no gaskets, just this stuff. Save the old gaskets in the event it don't werk, but it did werk for me on a 125HP. This material is the same formula as the OEM gasket maker GM uses on it's oil pans,in leu of a rubber gasket.<br />It's extremely flexable. It's probably useless in areas of very high pressure, but temp and flexing are what it's designed to handle...Just what the doctor ordered. After all you've been thru to this point, it couldn't hurt.

 

[speedwrench]

Re: Mystery still not solved

Thanks 12'er. Great idea, unfortunately it didn't cure problem ether.<br />Usually, when I'm chasing something like this, it's something simple that I've overlooked. Is there any gasket that can let water into cylinder from intake side? Clymer manual pics are not real clear on where water jackets are. ANY & ALL ideas are welcome.

 

[speedwrench]

Re: Mystery still not solved

???? Other than something involving LARGE hammers and/or explosives, already have those thoughts.

 

[jim dozier]

Re: Mystery still not solved

Have you pulled the powerhead. Is there a way for water to get into the exhaust ports by leaking past the powerhead base gasket. I don't know if that possible but there are only a few places where water can leak short of a cracked coolant jacket. Good luck with this mystery. It seems like you have covered all the bases. However when I lose my car keys I alway find them (so far) in a place I've already looked!

 

[speedwrench]

Re: Mystery still not solved

Thanks jimd. Yea I did. Changed both gaskets. Lower one tooked little used up, probably from having to pull power head to change exhaust plate and gaskets (3 times) but no obvious leakage. <br />Didn't change the water problem. <br /> While I had it running this last time I pulled the fuel recirculation lines off and let them blow into container. No water evident so must be coming from exhaust. Right? Right?<br /><br />My "friends" have suggested a garbage can and a 6 pac of Bars-Leak.

 

[speedwrench]

Re: Mystery still not solved

Ever seen a "tooked" gasket??? It's a south Texas thing. you wouldn't understand. <br /> Anyway, put engine in time out for next few days, off to Super 10 at SA, maybe win enough to hire "real" mechanic or buy her new engine. If anyone can think of anything to else to check, please post.

 

[speedwrench]

Re: Mystery still not solved

OK, didn't win enough to buy new 'board. Ready to get startrd again.<br />Any new ideas???????

 

[speedwrench]

Re: Mystery still not solved

Well, I can see by the reples that I'm not the only one stumped. <br /> Finally had time yesterday to pull power head back off. Both base gaskets look good.<br /> Developed way to pressure test water jacket. It holds 15psig for <10 minutes so I suppose it is safe to conclude that there are no cracks or gasket leaks in the power head water jackets. <br /> As I said, I'm a FNG on outboards, so spent a few hours searching past posts again. No real clear answer.<br /> Next question: Is there supposed to be any kind of check valve or whatever to keep water from backing up the exhaust or is it supposed to be wide open all the way out?<br /> And could a bad reed on #1 cause the problems I'm having? pulling water back into cylinder??? There was evidence that water was getting back into #1 intake port.

 

[wayne h]

Re: Mystery still not solved

did you check the cylinder for cavitation ?if you know diesel engines you know this is a problem it can be low in the cylinder and still have good compression. its just a thought i dont know alot about outboards but i am learning. but i am a diesel mechanic and know that wet sleaves are prone to cavitaion without the proper additives

 

[roscoe]

Re: Mystery still not solved

OK Wayne, what is cavitation in a cylinder?

 

[wayne h]

Re: Mystery still not solved

http://www.freeautoadvice.com/diesel/cav.html <br />this will explain it better then i can but it makes pinholes in the cylinder somtimes you cant even see them when the cylinder. but when heated from cylinder temp is when the problem starts. the engines i have rebuilt are very noticable.

 

[Tinkerer]

Re: Mystery still not solved

This probably won't be any help, but here goes anyway. Re pressure test: did you do it hot or cold? I had a problem with a 4 cycle once that only drew water in as engine cooled as crack was sealed by expansion when hot. Maybe reverse is possible too?

 

[OBJ]

Re: Mystery still not solved

Hi speedwrench.....read through the entire post....ya got a good one on yer hands....<br /><br />Bout' the only thing I could think of was to have the block magna-fluxed for cracks. Sometimes these suckers are hard ta' see. They only "open wide" when the engine is hot. <br /><br />Maybe just get another motor for the wife.....may reap benifits.....

 

[speedwrench]

Re: Mystery still not solved

Thanks for the ideas. <br />Well versed with the cavitation problem with Farmall/Ford engines, but this not a wet sleeve engine, and I did clean and inspect the water jackets with strong light and cheaters when had head and exhaust cover off.<br /> Hint: Carb cleaner will melt carbon out of exhaust like you wouldn't believe.<br /> Pressure test was cold since couldn't figure how to do it without pulling power head. With the small volume of air involved any leak should have shown up. When I first pressured it up it would leak down from 5# to nothing in about 10-15 seconds, had to use Snoop to find plug in thermostat tell-tale was seeping around threads Guess a crack could seal back up when cooled back off, but sure is sealing up tight. If test again, will use helium, it will get out of anything.<br /> Magnaflux won't work on non ferrous metals, have to use zylglow on aluminum, and have not had real good success using it without total disassembly and cleaning. Enough typing, go pull intake!!!!!

 

[speedwrench]

Re: Mystery still not solved

GOT IT!!!!!!!!!!!!! 1/2 one reed gone, corner knocked off other of the pair. Guess the pieces went out exhaust. They are gone! Must have shattered into small pieces, no marks anywhere on rod, piston or cylinder wall.<br />Looked in crankcase with borescope, no junk lodged anywhere. ???? <br /><br />NOW, where can I get just a replacement reed pair. Dealers here are about like going to Auto Zone. "Oh we can't look up Force." "No, if you bring it in we can't match it without a way to look it up and we can't look up Force" Beginning to understand why my mechanic commited sucide. He probally avoided a murder charge dealing with these people.

 

[adam171771]

Re: Mystery still not solved

How do the reeds affect water in your cylinder? I am going through the same thing..so just curious.

 

[KennyKenCan]

Re: Mystery still not solved

speedwrench,<br /><br />If the reed broke off and went thru the motor, I would suggest that you disassemble the entire engine and send the block and heads out to a reputable testing facility to check for cracks and damage.<br /><br />You will not be able to detect a small hole or crack visually, it must be done chemically or mechanically.<br /><br />Also check all moving components for damage.<br /><br />If the motor sucked down a reed, it most likely has done damage somewhere in there, and will need to be repaired!<br /><br />This is just my opinion.<br /><br />Kenny

 

[speedwrench]

Re: Mystery still not solved

KKC: Normally I would agree with you on tearing it down, but by now it has probally 4-5 hours (or more)run time on it since problem started. It runs fine, below 4000 rpm. There are no marks anywhere in the crankcase, rod, piston bottom, cylinder walls, piston skirts or top, or head to even give a clue where pieces went. From looks of reeds, my guess is it shattered into small pieces that must have went thru the exhaust. Inspected inside crankcase with bore scope, nothing lodged in there, water jackets # test good and no oil running down outside of crankcase, so think I will go with reed replacement, if can find some.<br /><br />Anyone have just 1 pair ??????????? Manual says they aren't serviceable but anyone with a phillips can do it. Hate to buy a whole set when just need one. E-mail me:dpatton@the-i.net<br /><br />77J175: Reeds are check valves in the intake manifold that keep crankcase diffential pressures<br />from blowing back thru carb when goes to pressure side to charge cylinders. Thats not very clear, can someone bail me out???

 

[jim dozier]

Re: Mystery still not solved

Speedwrench I'm glad you've found the problem. Let's hope its THE problem. I am also wondering though how a damaged reed allows water in the engine. I am familiar with their operation and effecst on the running of an engine, but what's the connection with the water?