water in cylnders

[loosechange]

have a 4.3 omc(chevy v 6) I keep getting water in the cylinders I have rebuilt motor twice and the third time used a reman short block had the heads checket both times (ok)replacer the exhaust flappers. now new motor does the same thing. dealer suggested that the ramps we put in at are to steep (not) the engine runs fine at startup and we dont have any problems untill we shut the engine down to fish then we get the the water in the cylinders. there is no water in the oil the only things that havent been replaced are the heads and the intake manifold we pickled the engine last time today I go back and have water in the cylinders again and we havent ran the boat. this is getting strange any help out there before I go nuts?

 

[Don S]

Re: water in cylnders

You probably have bad exhaust manifolds and risers. They are water cooled and have a life expectency of 5 to 8 years. Could even be the gasket between the riser and manifold or the surface where they go together is corroded away allowing water into the cylinders.

 

[tommays]

Re: water in cylnders

the manifolds and riser/elbows would be the most logical problem area<br /><br />how old are the parts your reuseing a crack can be hard to find even with testing<br /><br />are you getting water in both sides of the motor<br /><br />does the water allways enter the same cylinders<br /><br />is your elbow the correct hight above the water line when the boat is loaded every drive builder has a measurement that they have to be above or water will enter the motor<br /><br />tommays

 

[loosechange]

Re: water in cylnders

thanks for the info the risers are the old style one piece manifolds both are new. new gaskets with the rebuild what should the height be? we never removed the motor mounts from the boat so the height wouldn't change we are getting water on both sides of the motor

 

[tommays]

Re: water in cylnders

this a link that is a step by step for merc but it should be the same for your motor<br /><br /> http://www.boatfix.com/merc/Bullet/01/01_13.pdf <br /><br />it sounds like the risers were reused?? its a good place to look<br /><br />tommays

 

[Don S]

Re: water in cylnders

Does the engine diesel when you shut it off??? That would sure cause water to get into all the cylinders. The link tommays has in his reply addresses the problem, just wanted to ask in case you missed it.

 

[loosechange]

Re: water in cylnders

the risers are new and no the engine runs super except for the water. we brok in the motor for 20 hours without this problem this has been about the time all 3 of the motors went before this problem and thanks again for the help I am going to the site master jack sent now

 

[tommays]

Re: water in cylnders

if i understand you the samething has happened 3 times??<br /><br />if no parts are bad it would point to needing more rise in the riser/elbow combo by adding a spacer block if room allows<br /><br />tommays

 

[Don S]

Re: water in cylnders

Did you do any fishing during the breakin period. I'm thinking, like tommays, that when you are fishing and maybe you and friends and all the gear are in the stern, then with some wave action you are looking at water being deeper than the risers are high which lets water into the exhaust manifold and on into the cylinders.<br />A few more questions, are you in salt or brackish water, is your engine raw water cooled........and did you use marine head gaskets?

 

[Bondo]

Re: water in cylnders

I think Don,+ Tom are on the right track........<br /><br />First, You've got to get rid of those 1 piece manifold/risers..... They were an Idea that really Failed.... Badly.....<br />When you go to buy your set of 2 piece manifolds,+ risers, you'll want to get a set of 3" riser extension blocks......<br />The extra 3"s Should be enough to stop the water reversion.... I doubt you need to go that far, but 6" extensions are also available......<br />I'm told you need At Least 13"s from Water Level,(outside the boat) to the bottom of the exhaust passage in the Risers(in other words, where the exhaust Stops going Up,+ turns Down in it's direction of flow)........<br /><br />Hope this makes Some Sense to you..... I know I've Confused Myself...... <br />Do a search for an Old Boat Wrench named Vinny....<br />He's written Alot about "Static Line" in relation to Risers...... It'll be in the archives, within the last year or so.......<br /><br />Good Luck....

 

[loosechange]

Re: water in cylnders

thank you all for the help Ihave the service bulletin that master jack recommended I think you all are on the right track. will the new style risers fit and can you recommend a parts place online to look? I wish I had found you guys sooner!!I hope to be able to repay the favor soon thanks

 

[Don S]

Re: water in cylnders

What year engine are we being asked about. Hard to give specifics with out specific information.

 

[loosechange]

Re: water in cylnders

sorry it took so long to get back the engines are 1988 1 piece manifolds does any body make any thing else?

 

[Northern Eclipse]

Re: water in cylnders

You mention that the intake manifold is original have you had it checked for cracks or failing gaskets?. I'm also with Bondo about static line also, Just thought you might want is check whats been done and whats there before you shell out big bucks.