hogie roll

Starboard engine was running poorly last weekend and did not want to idle. Eventually threw the 3-2 code for MAP sensor.

Tinkered with it tonight, replaced IAC. Didn't help. Swapped MAP sensors, no change.

So I pulled plugs, two lower plugs on one bank were wet. Checked dipstick to find a nice brown milkshake.

Is the head gasket popped? Can it be saved? Based on some research I just did I should pull the oil ASAP.

The last time it overheated would have been about 40hrs ago when I replaced the impellers but the key slipped out when I was sliding the impeller on. I'm not sure how long my dad ran it, but the alarm did go off.

Also, I idled it for a period of time the night before I had the issue while I was beached on muddy bank to ride out a storm. My buddy noticed that it was steaming from that engine. Could it ingest water from being run in the rain? It did not overheat in that instance.

mrv8outboard

Clear the cylinders and do a compression test. A leak down would be more accurate. I would change the oil and filter to save as much of the internals as possible. Have the block and head anodes been changed on a regular basis? Lower seals can ingest water. Bad,open thermostat can cause moisture in the oil as well. Exhaust as well. Internal corrosion from lack of anode protection is a possibility.

BUP

iTrader: (9)

Agree and yes lower seals bad especially from an over heat. also 4 stroke outboards really needs a properly operating T Stat and the correct degree one. Agree bad valve(s) can cause water reversion in any 4 stroke engine on the water. Also waterline height can cause water reversion. Would do the comp test and then move on to leak down testing. Is the spark plugs wet and or rusty after you pulled them. I would crank over engine with all spark plugs out and really fog up the cylinders ASAP and take care of the motor oil and filter milk out as well completely then fresh motor oil and filter.

There is few other issues but I have to think about what exactly it is or can ask some of my outboard friends. Will need the engine serial number . Total engine hours and any saltwater use - if so how much will need to that as well.

hogie roll

There is water in two cylinders.

My research says that popped head gaskets and cracked blocks are not uncommon on early DF250s.

I've had them alarm a couple times for overheat when backing off something or spinning with throttle. I think this one may have gotten hot when I didn't get the impeller key in. My dad drove it for a bit but I'm not sure how long.

hogie roll

These engines have 700 hours. I did the 600 hr maintenance at 660hrs which included replacing all of the anodes.

When I got the boat with 550hrs on the engines I would geuss it was 90% freshwater hours. Since then it has probably been 50/50.