engine alarm and white smoke!

[jwclbi]

Hello, heres an interesting one. Im running back home and all of a sudden the alarm goes off and my 225 efi merc is blowing white smoke out of the exhaust! Im thinking blown gasket. I stop the boat let it idle for a couple seconds shut it off and check a few things. water was pumping, oil level was fine. Was getting dark soon so i thought well let me see what happens if i fire it up again. start it up, runs fine, no white smoke, no alarm. Ran perfect the rest of the way back, about 20 minutes. maybe a thermostat got stuck? any thoughts would be cool. thanks

[Bushwacker]

Is this an OB or I/O?

[Blue_Heron]

Originally Posted by jwclbi

...all of a sudden the alarm goes off...

Constant alarm tone, or pulsed? The solid tone is temp, the pulsed tone is oil injection.

White smoke could be oil smoke, or it could be steam...

It could be as simple as picking up a plastic bag on the lower unit that blocked the water intakes. When you stopped, the bag washed off and the engine was able to cool down. Or it could be something completely different. I'm just indulging in wild speculation. If it was the oil alarm, I don't have a guess.

Dave

[Fr. Frank]

Dave is likely correct. Continuous tone is a temp alarm, continuously beeping is no oil flow, (3 beeps is low oil level in the tank, 4 beeps is water in the high pressure fuel tank, etcetera.)

And like Dave, I would suspect a temporary obstruction of the water intakes.

[jwclbi]

thanks, sorry outboard. yes continuous alarm and engine would run above 1500 rpm. low oil alarm will not allow engine to run more than 1500 rpm or so. alarm went off when i was running about 3000rpm. as soon as it went off i looked back and saw the smoke at the same time the tell tale was pissing water as normal, so I'm thinking perhaps the water pick up was fine?

[Blue_Heron]

Originally Posted by jwclbi

...I looked back and saw the smoke at the same time the tell tale was pissing water as normal, so I'm thinking perhaps the water pick up was fine?

If the tell tale was squirting, you probably didn't have an intake blockage. Could you tell if it was white smoke, or was it steam? Steam would have dissipated quickly, smoke would have lingered. Where was it coming from? The exhaust port on the mid-section? The through prop exhaust? From under the cowl (through the cowl vents)?
Dave

[jwclbi]

yeah pretty sure the pick up wasn't blocked. 100% sure it was white smoke out of the exhaust at the midsection, same exhaust port that blows tons of the blue 2 stroke smoke out when i fire it up!