Sudden Loss of Power - Dead Engine

[Mainiac Boater]

I have a 2001 Sugar Sand Tango with a 2005 175hp Mercury XR2 sport jet. I had the boat on the water yesterday for about an hour. While cruising at about 3800 RPM I suddenly lost power. RPMs dropped to about 2800-3000, enough for the boat to come off plane. I initially thought the throttle linkage may have come loose because I immediately brought the throttle lever to the neutral position but the engine still ran at about 2800 rpm. I continued to fiddle with the throttle lever and the engine briefly regained power only to lose it again. Shortly thereafter I heard a clunk and the engine quit. The whole ordeal probably lasted 20 seconds. I attempted to start it once but the engine would not turn over. The engine was warm to the touch but you could keep your hands on it. No warning buzzers at all. I trailered it home and discovered that the flywheel will not turn.

Did my motor just blowup? I am marginally mechanical so I would like to troubleshoot the obvious things myself. Any suggestions on where to start?

 

[Silvertip]

Re: Sudden Loss of Power - Dead Engine

Either the engine seized or the lower unit locked up but my bet is the engine seized. You can drop the lower unit and if the engine now spins, the lower unit is the culprit. If the engine still can't be turned over the power head is locked up. Pull the plugs and have a peak at them. Were there no warning beeps? Power head failure is typically due to a "lean" fuel mixture or overheat condition. Reading the plugs and looking into each cylinder can generally tell you what happened. While oil injection failures do happen, this is not at the top of the list of causes but certainly possible.

 

[Mainiac Boater]

Re: Sudden Loss of Power - Dead Engine

No warning beeps. I did look through the nozzle and intake grate to check out the impeller to see if I could see anything awry. Nothing. I plan on checking the plugs this evening.

Man, this is going to be painful if the motor is shot. First boat, only owned it since last fall, used it only 3 months. I was leary of oil injection as all my boating experience is pre-mixed. I know its too early to tell, but if it turns out oil injection casued the problem with no warning buzzer, I am going to be even more peaved than I am right now....with nobody to take it out on.

 

[Mainiac Boater]

Re: Sudden Loss of Power - Dead Engine

Engine is blown. Ouch. I didn't notice yesterday as the sunlight was fading but there was metal chunks/shavings all over the bilge by the engine. I beleive a rod let go and knocked a hole in the block by the crankshaft. I guess I'm done boating for at least 3 or 4 years. It was a fun Sept 2010 and June 2011 while it lasted. Man this sucks.

 

[j_martin]

Re: Sudden Loss of Power - Dead Engine

Before it blew, did you get a few test beeps when you turned on the key?

 

[Mainiac Boater]

Re: Sudden Loss of Power - Dead Engine

Before it blew, did you get a few test beeps when you turned on the key?

Only beep was when I started the boat. Turn the key. Long beep, then start. No warning when it was operating. I am pissed right now.

 

[j_martin]

Re: Sudden Loss of Power - Dead Engine

I can't help you emotionally. Only trying to help you figure out what happened. They usually beep a long beep, and two to 5 short ones. (different modules beep a little different.) No beep would be a clue that the alarm is inoperative. Sounds like lack of oil wasn't the problem. If the alarm is working, it would be almost impossible to be without oil more than 2 seconds without the alarm sounding. It is possible that if you couldn't hear a rod ventilating the block, you couldn't hear an alarm.

 

[Faztbullet]

Re: Sudden Loss of Power - Dead Engine

Typical sport jet failure, more likely water in cylinder caused it it "pop". Motors are so scarce that they "stolen" quite often from the area marinas around here...

 

[Mainiac Boater]

Re: Sudden Loss of Power - Dead Engine

I can't help you emotionally. Only trying to help you figure out what happened. They usually beep a long beep, and two to 5 short ones. (different modules beep a little different.) No beep would be a clue that the alarm is inoperative. Sounds like lack of oil wasn't the problem. If the alarm is working, it would be almost impossible to be without oil more than 2 seconds without the alarm sounding. It is possible that if you couldn't hear a rod ventilating the block, you couldn't hear an alarm.

The warning buzzer functioned the same as it always did when I started it. It never got noisy when the malfuntion happened. Just a loss of rpms and then a sudden clunk. The clunk I'm guessing was the rod looking for daylight.

 

[Mainiac Boater]

Re: Sudden Loss of Power - Dead Engine

Typical sport jet failure, more likely water in cylinder caused it it "pop". Motors are so scarce that they "stolen" quite often from the area marinas around here...

What would cause water to get in the cylinder?