locked up 4.3

[dmorley]

Mystery. Two weeks ago I checked the compression on my motor and it was bad (90 to 165 lbs). The mechanic just today pulled the engine and said it was locked up and couldn't even get the crank to turn with the plugs out. It goes into the machinist next week for a rebuild anyway, but my question is there any thing the mechanic could have done pulling the engine that really screwed it up?<br />Thanks

 

[crazy charlie]

Re: locked up 4.3

If he pulled the manifolds off w/o draining them he could have ingested water into the cyls.Though it would have to be sitting for quite a while to lock everything up.Charlie

 

[dmorley]

Re: locked up 4.3

No, I drained the manifolds this fall and he just pulled the motor today.

 

[dick]

Re: locked up 4.3

no

 

[outboardguy]

Re: locked up 4.3

Possible head gaskets were leaking and left some water on top of the cylinders after you last ran it.

 

[Bondo]

Re: locked up 4.3

and couldn't even get the crank to turn with the plugs out .

I Don't know Why......<br />But, It Ain't Water.....

 

[BRIAN03]

Re: locked up 4.3

If the engine did'nt overheat its not a head gasket. Check the exhaust manifolds and look to see if these is rust in the exhaust side. The engine is locked up from rusted cylinders wall and rings. The problem is in the exhaust not the engine. The problem is the height of the exhaust. If you dont change the static line you will fill the new/rebuilt engine up again and waste all you money repairing or relplacing the engine. The engine isnt the problem its the installation of the exhaust in the boat. The 4.3 has the most pull on the exhaust on the compression stroke. Make sure the person doing the work has a clue about static line. Or you will be doing this all over again. If the engine has one piece exhaust manifolds they dont work. You need to install center mount exhaust manifolds with extensions 3" or 6" put the most you can fit under the engine cover. Make sure you have the new design exhaust shutters.

 

[dmorley]

Re: locked up 4.3

Brian,<br />The static line is about 17-18 inches, however, you are absolutely right about the one piece manifolds being a problem and have ordered a new Y-pipe and two piece manifolds/risers. I'm almost certain these did cause repeated ingestions of small amounts of water that went undetected. The thing that puzzels me is that after the compression check two weeks ago the boat never went near water. I did, however, leave the spark plugs out, but the engine cover was on and outside moisture shouldn't have gotton in.

 

[Walt T]

Re: locked up 4.3

I would be suspicious if a locked up engine gets rebuilt. Ask to see the engine after disassembly and you want to see the damamged parts.

 

[dmorley]

Re: locked up 4.3

In case anybody is curious. The machinist took the heads off and sprayed oil in the cylinders and left it over night. The next day it freed up. It appears that leaving the spark plugs out for even less than 2 weeks created enough rust in the cylinders to lock it up. He's going to bore and hone the cylinders and that should fix the problem--actually he doing a total rebuild. Incidentally, he did confirm that water was getting back into the heads from the one piece Mercury manifolds.

 

[Bondo]

Re: locked up 4.3

Yep, <br />That All Makes Sense.........<br />Glad to hear you've got it headed the right way..... <br />You ARE getting a New Set of manifolds ??? Right ???<br />For another hundred or two, Your Machinist could do a Full Engine Balance job on it.....<br />You'll be building Longevity into it that way....

 

[dmorley]

Re: locked up 4.3

Bondo,<br />The new manifolds and risers got here today. I'll need to go through the old posts to figure out how to convert my FWC half system to full.<br />Don