Water in cylinder

[boat boat boat]

I have recently acquired an '84 140hp v4 2 stroke.

I have slowly been dealing with the problems that arise from lack of maintenance over the years. The most recent of which is water in the port side top cylinder. I just replaced the head gasket but have the same problem. Can water be drawn in from the exhaust side? Is there anywhere else i should be looking?

thanks

 

[jakelogsdon]

Re: Water in cylinder

Compression check??

 

[boat boat boat]

Re: Water in cylinder

Had it checked before i bought it and they were all fine. That was only a couple months ago and it hasn't overheated or anything.

 

[jakelogsdon]

Re: Water in cylinder

The water is isolated to that one cylinder only?

 

[boat boat boat]

Re: Water in cylinder

yes. Milky white spark plug and white cylinder head when i pulled it off. Only on port side top. The other three are fine.

 

[boat boat boat]

Re: Water in cylinder

Just pulled off the exaust manafold and found milky white water/oil emlusion all over the exaust side. I cant quite figgure out why it would only pull the water into the top cylinder if the gaskets are bad. Wouldnt the water get pulled into both #2 and #4 the top and bottom?

Anyway, the new gaskets will be here Tuesday so i guess we will see if that is the problem.
Anyone have an idea as to where else the water would be coming from?

thanks
FS

 

[boat boat boat]

Re: Water in cylinder

So i changed the exhaust gaskets tonight and no change. Still water in #2. Where is it coming from??? Any idea where to look next??

 

[Bluefish]

Re: Water in cylinder

Did you check the head warp age I believe 3 or 4 thousand is max if more you can wet sand them down

 

[boat boat boat]

Re: Water in cylinder

Can I take the head off again without needing to buy another head gasket? And what is the best way to tell if the head is warped?

 

[jeffersondodson561]

Re: Water in cylinder

The problem may not be with your heads, between the two banks of cylinders is where the exhaust gases escape, this area does have cooling water in it as well, you might want to after verifying warpage, check there too. I have run into this on one occasion on an OMC, being that Yamaha's blocks are very similiar to OMC I would scrape and replace all of these gaskets.

 

[99yam40]

Re: Water in cylinder

Can I take the head off again without needing to buy another head gasket? And what is the best way to tell if the head is warped?

no you will need a new gasket every time you pull the head.
Manual calls for using a metal straight edge and feeler gauges for checking the head for warpage
Do you have a Yamaha service manual? If not get one and read up. It will pay for itself many times over. Could be a cracked head or block

 

[boat boat boat]

Re: Water in cylinder

Had the head shaved today and put on another head gasket. Same problem. Did another compression test and they are all the same (10bar). So its not a cracked block right? Looks like im on to the exhaust side again, I should buy stock in gaskets.

 

[99yam40]

Re: Water in cylinder

boat you have a PM

 

[boat boat boat]

Re: Water in cylinder

This will be the first engine that I take to a mechanic. It has been suggested that i might have a pin hole in one of the castings, and that a leak down test would help find it since I cant see it.

I dont have the tools, so she goes in on Thursday. Thanks for all the suggestions and Ill let everyone know what is up when I find out.

FS

 

[boat boat boat]

Re: Water in cylinder

So there is a pinhole in the exhaust manifold that is pointing directly into the exhaust port of the #2 cylinder, which is why there was no water in #3. $100 to weld her up and we are back in the water early next week.

Thanks to everyone for the help

FS