97 Sea Ray 4.3

[stardog]

Hello all,

I have a 97 Sea Ray 175 with a 4.3. I have only owned the boat for a year, and I thought the motor never seemed quite right. It always had hard starts and lacking in power. I drained the oil and it was a nice tan milkshake. I replaced the manifolds and risers this past summer. Pulled the plugs, and all looked normal except cylinder #1. I was a powdery rust color. Tested the compression, and all cylinders were 188 except #1. It was at 150. I pulled the intake and it looked fairly normal, but very rusty. The water passages on the heads looked horrible. Also, the were orange streaks in each intake passage as if a drop of water had gone down. No visible cracks on the motor or intake. Any ideas on the water in the oil, and the orange plug? Time for a new motor? Any suggestions are appreciated.

Thanks,
John L
Bethlehem, GA
97 Sea Ray 175 4.3

 

[Rick Stephens]

If it got cracked in a freeze the most common weak spots in that block are inside the lifter galley just above the lifters and the heads between cylinders on the inner/intake side.

When you replaced exhaust did you inspect the shutters?

Rick

 

[Bondo]

Also, the were orange streaks in each intake passage as if a drop of water had gone down.

Ayuh,.... Welcome Aboard,... Streaks from where, to where,..??

Water flows downhill, so the leak is at the top of the rust streaks,....

 

[stardog]

The exhaust shutters were fine. The streaks of rust look like they came down from the intake manifold into the heads. What do you guys think of the compression numbers?

Thanks,

John L
Bethlehem, GA
97 Sea Ray175 4.3

 

[alldodge]

The exhaust shutters were fine. The streaks of rust look like they came down from the intake manifold into the heads. What do you guys think of the compression numbers?

Thanks,

John L
Bethlehem, GA
97 Sea Ray175 4.3

Tested the compression, and all cylinders were 188 except #1. It was at 150.

The 150 looks good but the 188 leads me to think your leaking water in the cylinder or you have a bad gauge. Numbers should be in the 150 range. Either crack or gasket

 

[Mercruiser420]

A leak down test will tell you why cylinder 1 is lower than the other 5. Rust in all the intake ports may indicate some water in the fuel system

 

[stardog]

The compression gauge is pretty accurate. I checked it against my Sea Doo, and it was spot on. I don't see how there could be water in the fuel. Recently pulled the tank and cleaned it. Not saying it couldn't happen though...I agree on the leak down test. Guess I was hoping for a quick and easy answer. Seems as if the water in the oil and the compression are probably not related.

Thanks,

John L
Bethlehem, GA
97 Sea Ray 175 4.3

 

[alldodge]

Didn't mention it about having water in the fuel. The reading is high enough to make me think there could be water or oil in the cylinders.

Either way my bad, just looked at manual 18 and it shows the psi at 180

 

[stardog]

I believe the manual says the lowest compression number needs to be within 70% of the rest. I guess technically it is in spec, but there has to be something going on. Trying to avoid pulling the heads. Tempted to just call Rapido marine for another 4.3.

Thanks,

John L
Bethlehem, GA
97 Sea Ray 175 4.3

 

[Mercruiser420]

10-15% not 70. What was your leak down results?