2000 mercruiser 4.3 knock no start

[Ngmedic]

Good day I am happy to have this forum but very upset to be posting because this is just no good. Please help me as I struggle through the description of what has happend and any advice is helpful.

I have a 2000 caravelle 188 with a 4.3 mercury mercruiser with a alpha 1.

Bought this boat from.my friend I rode in it with him for years never a problem.

Ran it 4 times on my own. This time it started and I ran it for 5 minutes had to stop the motor to get a lost hat. Went to start it all I got was a loud buzz from the starter. I was told by the person that towed us it was a bad gear in the starter. I took it home and pulled the old starter took the starter apart and the plastic gear on the inside was just shredded up so I thought I was in the clear bought a new marine starter and installed it.

Went to start it up and I am now getting a loud grinding noise like a garbage disposal with a rock in it. I turned the key and saw the belt trys and jump forward but it will not spin it just makes the grinding sound and no movement . I have a boat mechanic friend who is out of town. He told me to see if I could manually crank the motor with a breaker bar. And I am able to move it with alot of force .

he gave an idea that the pinion on the new starter may be screwed up and sticking or not engaging?

Also from what i could see the teeth on the flywheel are all in tact.

I know nothing about boat motors but am handy moderate car stuff. To me it feels like I'm am completely screwed. It sounds like something is seriously broken inside.

Thank you

 

[alldodge]

had to stop the motor to get a lost hat

My assumption is you stopped real quick

boat mechanic friend who is out of town. He told me to see if I could manually crank the motor with a breaker bar.

Not a good idea, because cranking the motor with a breaker bar could snap the crank bolt.

Remove the plugs are crank the motor over, I think you ingested water into the cylinders and it needs to get out of there ASAP

 

[Ngmedic]

My assumption is you stopped real quick



Not a good idea, because cranking the motor with a breaker bar could snap the crank bolt.

Remove the plugs are crank the motor over, I think you ingested water into the cylinders and it needs to get out of there.

How do I get the water out?

 

[achris]

Hello Ngmedic and :welcome: aboard.

In order to better help you would you be so kind as to provide the engine serial number. A 2000 boat with a gen one engine means it's not the original engine.... That's why we ask details of the engine, and don't really care what boat it's in...

Chris....

 

[Rick Stephens]

How do I get the water out?

With the plugs out, when you spin or hand crank the motor any water will come out the plug holes.

 

[QBhoy]

Also thinking that you may have taken water back up the exhaust into the cylinders. 100% take the plugs out and see if she will turn over.

 

[Ngmedic]

Also thinking that you may have taken water back up the exhaust into the cylinders. 100% take the plugs out and see if she will turn over.

Lots of water currently turning by hand lots of water. How long do I crank. What else do I need to do

 

[Ngmedic]

Ok so plugs have been pulled . It now cranks by hand and when I turn the key. There was a whole lot of water. Mainly in the cylinders neer the back? What move do I make next

 

[Lou C]

Spray fogging oil in the cyls and crank it over again with the plugs out. Put the plugs in and hook up the water ears and see if it will start. You want to run it ASAP get it warmed up and change the oil to get any water out...

Next you will have to drain the exhaust manifolds and elbows. Then I’d remove the elbows to see if the exhaust shutters are in place at the top of the Y pipe. Make sure they work the way they are supposed to. Thee can be damaged by overheats. If they are not there then you have to replace them but Furst try to fine the old ones, they could be stuck in the bottom of the Y pipe.
id also prob check the manifolds & elbows for corrosion and blockage, leaks at the elbow/manifold joint can leak water in a cyl if you have the wet joint exhaust style ( pre 2002)...

 

[Rick Stephens]

↑ That... and change the oil.

 

[QBhoy]

Turn it over in bursts as all ready said. Digging oil or two stroke down each bore will help too.
Defo change the oil at least once..preferably more.
Has the boat previously overheated and ruined the exhaust flappers. These usually help stop water coming back up and in.
Was this the first run out since winter ?

 

[Ngmedic]

Ok everyone thank you so much for all of the advice here is an update.

After cranking the engine multiple times with no plugs I fogged it cranked again and put the old plugs in. Muffs on and after slight hesitation it started up and ran very well. Ran it for a few minutes with no issues. Turned it off and re started no problem.

My plan of action now is to do an oil change, and I am researching how to do what Lou C suggested. and am going to put new spark plugs in while I'm at it. Is there any advice or other things you all think I should do? I live at the lake and only go during the week when tourists are gone so i don't mind being out of commission for a few more days to ensure a good outcome. Thank you!

 

[alldodge]

Sounds like your going to be good, run her so it can burn off any moister left behind

 

[Ngmedic]

Ok so I have done what I've been told so far but cannot figure out the elbow draining.

I have a concern. I drained the oil put a new filter on and filled with new oil. ran it up to operating temperature and everything sounds fine it's not getting hot or anything like that. But now the new oil is milky. Now I noticed immediately after filling with the new oil the dipstick still had bad oil. But even after running it I would think the new oil would over run the old and at least dilute it so it would be cleaner on the dipstick?. Is this just more water in the engine or is something cracked. How many would changes should it take to clear this out if something isn't cracked and letting water in.
Like I said it runs great I just feel.like this is a concern

 

[alldodge]

Water being heavier then oil flows to the bottom, so in most cases not all the water comes out. If the motor reaches temps hot enough to burn the water off (oil at 212*) then the moisture will burn off. Oil temps will be hotter then water

If your not seeing oil raise then no new water is going in.