Outdrive SEIZED?!

Has anyone ever heard of this? ...

Mercruiser 220hp V-8 w/ Alpha One outdrive. 120 hours. Serviced about 20 hours ago. Engine oil and outdrive oil are full and good.

Anyway, so I woke up at 6am this morning and hit the lake. We cruised away from the marina while the sack was filling and the engine was warming up. OK, it was time to go so I shut off the engine and my friend jumped in the water.

All set...turn the key...bam! (clang, bang, whack...whatever you want to call it). That thing wasn't turning over. I tried it a couple more times after fiddling with the shifter...neutral, forward, reverse, wiggle, wiggle....bam!

So...what's up?! I'm suspecting the outdrive because I don't think the engine seized (I had oil pressure plus it happened after shut-off, not while running) and I can't imagine how I could have gotten enough gas in a cylinder for hydraulic lock (but who knows?).

The only clues are:

1. The engine dieseled a bit when I shut it off. This has happened before but mostly only when shutting it off after cruising somewhere quickly.

2. The transmission has been kind of hard to get in gear a few times. I had to wiggle the lever and pull up on it a bit. I figured this was just a cable adjustment thing.

Other than that, there was nothing out of the ordinary. I'll have a mechanic check it out next week but I thought I see if anyone has any thoughts. Whatever it was, it didn't sound cheap.

Oh, and to add insult to injury, there were no other boats out at 7am so we had to swim/paddle the boat about 3/4 of a mile back to the marina.

P.S. If anyone knows a really good Mercruiser mechanic in Austin, let me know.

it sounds like you sucked the lake up thru your exhaust. pull the plugs and see if you can turn the motor over with a breaker bar. if water comes out of any cylinders, pour a tablespoon of atf or oil in every cylinder. your dipstick may not show any water, but change the oil anyway. some people put a little simple green in the oil , but you should research that somewhat.

if it won't turn over with the plugs out, remove the outdrive and see if it will turn over then. run it for 30 seconds tops and it is going to be very loud.


your flappers are m.i.a. fix them before you bend a rod or blow it up. get the new style flappers and don't shut off the boat while it is warming up or back off the throttle abruptly.


sink or swim

Thomas,

Thanks for the suggestion. My exhaust is through the outdrive and I didn't stop very quickly BUT I have a new theory: I'm thinking that it might be possible for the engine to diesel backwards for a moment, depending on exactly how it stops...maybe just enough to suck water up the exhaust. I'll go pull the plugs tomorrow and find out.

taking the plugs out and seeing if it will turn over is a good idea.

If it still won't turn over try putting a large socket wrench on the main pully and turning the engine *backwards*. You may want to remove the belt from the water pump before doing this just to keep from bending all the vanes backwards (it will also make turning the engine a bit easier).

If it won't turn either direction then I would say that something in the outdrive siezed up solid. If it will turn a 1/2 a turn or so and then stop again I would guess that the problem is beween the engine and outdrive. Some outdrives have universal joints and if they break this is often the symtom.

Bad news is that it is a major job to replace the universals.....

rod

the universals usually fail when the engine is started frequently with the outdrive in the "trailer" position. sometimes you'll see wallies doing this all the way to the no-wake bouys.

Lemme get this straight, the engine won't turn over?

Maybe water lock then.

Or spline shaft.

Hope it's not too serious, but...

I did the exact same thing with my volvo. end result=water in engine and impeller exploded. I pulled all plugs and cranked till the water was gone,sprayed wd in the cylinders,changed the oil 4 times andreplaced impeller. It sux to have to paddle your boat to the dock....good luck

Update:

Well, that was it. The dieseling sucked water up through the exhaust into the cylinders and caused hydraulic lock.

I...

1. Checked the oil
2. Pulled the plugs (starboard side was wet)
3. Sprayed some anti-corrosive lubricant into the cylinders
4. Cranked the engine (water blew out of the starboard side).
5. Sprayed more lube in there.
6. Replaced the plugs
7. Fired it up and let it run a few minutes.

It looks like everything is fine but I'm suspecting a problem with the starboard side exhaust flap since that was the only side with the water. I'll probably change the oil and check the flap before I take it out again.

Anyway, I learned a few things:

1. Dieseling is BAD on a boat so you should do everything you can to avoid it. This includes idling for a minute before shutting the boat off after you've run for a while (and heated up the pistons). I'd never heard of this and it isn't in the manual. I guess I learned the hard way (thankfully not the hardest way).

2. Exhaust flaps are important. If you have external flaps, make sure they're good. Transom exhausts can be particularly bad because if you simply stop too fast and get water up there while the engine is actually running, you might bend a rod. I didn't have that problem because the starter wasn't strong enough.

3. Maybe it's a good idea to have a spark plug wrench and some anti-corrosive lubricant in the boat just in case. If I had recognized the problem and had those things, I could have fixed the problem on the water and avoided an hour of swimming/paddling the boat.

paul,

What happened to your impeller? I might go ahead and change mine now if there is a reason to do so.

Taco,

Sounds like you have a similar setup (Merc 5.7 210 hp with Alpha 1). Because this is a carb engine they have a tendancey to diesel on shutdown. Mine did this quite a bit when new. A mechanic told me always let it idle for 2-5 minutes before shutdown to burn any excess fuel in the bowl to avoid run on when you turn it off.

ST-the fins on the impeller ALL broke or ripped off. I replaced it and all is ok. Just watch your water temp gauge.