Engine Ran without water for 5 minutes. PLease help

[aleestma]

PLEASE HELP
I was getting our 252SD ready for tomorrow in our driveway tonight. I turned the engines on just to make sure that they were working- I typically do this for about 5 seconds each engine because they aren't connected to water.

When I turned the port engine on I immediately got a check engine and then I couldn't turn the engine off. It was the strangest thing. I scrambled to turn the batteries off and even tho the batteries were turned off the engine wouldn't shut down. I disconnected the batteries positive and negative - wouldnt turn off. I scambled to get the water hose connected but the connector wouldn't thread. I jammed water in the inlet as best as I could while I was on the phone with the dealer but the overtemp alarm came on and then the engine started smoking. My son yelled pull the kill switch and that actually turned it off.

All told it probably ran for 5 minutes out of water - probably got some water in it but not great. What can I expect and what should I inspect.

 

[Cobra Jet Steering LLC]

if that ever happens again just open the rear hatch it shuts off both engines
it may be a computer malfunction so it may be covered under warranty

 

[buckbuck]

I am not that familar with the 1.8 motors but I would venture to say nothing bad happened. You did not increase RPM above idle. Yamaha builds a pretty good engine which can take alot of abuse. The smoke you saw was probably steam from the water hitting the exhaust manifold. Just to be proactive you might want to change the oil. Then take it out and listen to it run on the water. Keep us updated.

 

[MrBubbaGump]

I had a similar thing happen to me multiple times... Luckily I was on the water each time. Turned off the key, the engine stayed on, pulled safety lanyard still stayed on, turned off batteries yup still running. I then cranked the engine again and thats what killed it. Ended up being a bad ground on the ignition. Whats crazy is the boat was less than a year old!

 

[TeenGee]

Some of the plastic exhaust system parts may be compromised due to hot exhaust with no cooling water.

 

[1WetBoat]

Same thing happened to mine while I was out on the water right when I first got it. Same situation as @MrBubbaGump except in my case I pulled the ECM plug in the engine bay and that shut off my engine. It turns out it was a bad ground also.