Motor Locked up

[rgsterling]

So I have a 21 ft stingray with a 4.3LX mercruiser that seems to have locked up. The entire story is that I was out for about 2 hours, it was rough so I was running about 2500 rpms the entire time, ran fine the entire time. Got it back home hooked the hose to it to flush the motor and it made about a half of a turn and locked up. I replaced the starter thinking maybe it went bad but not the issue. I tried turning the motor over by hand and got it to move but it was difficult. After I turned it by hand a little I tried starting it again and it turned over and a loud knocking sound started so I stopped trying to start it. Has oil and the oil looks fine. I didn't have much time to really look at anything else other then the starter, with winter here I winterized it and figured I would have to pull the motor in the spring. Anybody have any ideas?

Thanks
Garrett

 

[Fishermark]

Re: Motor Locked up

Pull the drive and see if the problem is with the drive instead of the engine. Also pull the spark plugs and see if there is any water that comes out.

 

[thumpar]

Re: Motor Locked up

My first guess is water in the cylinders.

 

[Bondo]

Re: Motor Locked up

My first guess is water in the cylinders.

Ayuh,.... Probably from loadin' onto the wagon in rough water,....

Welcome Aboard Garrett,.... Like Mark said, pull the drive, 'n run it to see if the knock goes away,...

Pull the spark plugs, 'n look for signs of water, before ya light it off again,...

Hopefully, ya didn't bend a rod, pushin' against the water, with the starter,...

 

[stonyloam]

Re: Motor Locked up

If you do find water in the cylinders, check to make sure your exhaust shutters are in good shape. Good shutters will help to prevent it from happening again.

 

[rgsterling]

Re: Motor Locked up

Its just seems weird to me that it all happened at the ramp. And I had it hooked up to the hose within 15 minutes.

 

[Bondo]

Re: Motor Locked up

Its just seems weird to me that it all happened at the ramp. And I had it hooked up to the hose within 15 minutes.

Ayuh,.... The hull gets to be at an extreme angle durin' the retrieve, lowerin' the transom, below it's normal water level,...

Water can seep past the shutters, or Rush past where the shutters are supposed to be, if they're burnt up, 'n gone,...

I mentioned it, as it's a very plausible scenario,...
It only takes seconds below water level for the water to rush into the manifolds, 'n then the cylinders,...