1995 4.3 Mercruiser

[Terry Brown]

I have a 1995 4.3 in a boat I have had for 8 years...It has 350 hrs on it....
I have winterized it the same way all of this time...( directions from Mercstuff.com). Anyway, I flushed it out 2 weeks ago, and it ran fine. I went to the lake, two weeks later and it was hydro-locked. Water in the back two cylinders on the right side sitting in the drivers seat...Some say a cracked block..I am doubting this as we have had far severer winters here, and I have alway's done the winterizing the same. Maybe a head gasket ? I had issues with the exhuast flappers about four years ago.. I installed the updated ones... I checked them, and they looked fine. I also read in a repair manual that the exhaust manifold/ riser needs servicing after 300 hours...They gave 4 reasons for water in the combustion chamber, and this is one of them, saying corrosion can let water in this way...They also mentioned loose head bolts, a head gasket, and the worst a cracked block. I changed the oil last fall, and it is not contaminated. I am a heavy equipment mechanic....I don't know anything about the exhaust system on this motor...How does it work ? Any help would be a start.

Terry

 

[BAYLINER185]

Re: 1995 4.3 Mercruiser

Terry

Somwhere on here very recently DON S posted a cooling diagram. It would be what your asking for. I dont see a search feature on here or I would have looked for it and posted it.

Give Don a second he'll be along with the answer. This guy knows his SH^&

All I can tell you is that water flows through the risers then through the manifolds and then down the Y pipe and out the prop. Along with exhaust gas. ( very basic description )

 

[DockedPay]

Re: 1995 4.3 Mercruiser

I thought the Don S diagram was so helpful I wrote down the thread...use the search for "cooling question mercruiser"thread by "Al Slowhand"

 

[Terry Brown]

Re: 1995 4.3 Mercruiser

Thanks for the reply.....I will do the search and maybe see how it works....

thanks

Terry