Hi Guys, first time posting. I have a 4.3L I/O Mercrusier in a Fourwinns 21’ bow rider. I live in Ontario, Canada and have had the boat in the water for 6 weeks. It’s been running great. I had the block rebuilt two seasons ago, only about 25 hrs on it and I don’t drive it hard. Last week I was out on the water and was cruising about 25kph and slowed down and did a sharp U-turn and stopped. I sat for awhile and noticed oily discharge coming from the sump pump. Opened the “hood” and saw oil milkshake all over the top of the motor. It was coming out of the vent tubes of the valve covers. Took it back to the dock (5 min) and ext day took to launch, (5 min). I drained the block and about a gallon of water came out. I tested the cooling system by removing the pipe to the power steering and plugged it, removed the pipes to the exhaust manifolds and plugged one and pumped air into the other. Heard water gurgle and some air coming from valve cover vent tube.
question 1) is it 100% a cracked block? Or could the water have gotten in through my flapper when I banked and stopped.
question 2) if it is a cracked block, how could I have possibly cracked it??
question 1) is it 100% a cracked block? Or could the water have gotten in through my flapper when I banked and stopped.
question 2) if it is a cracked block, how could I have possibly cracked it??