41 thoughts on “MAJOR BOAT ENGINE REPAIR (part 1)

  1. wish I lived closer just to help the last boat I did a engine swap it was a 455 olds I have a 305  gm. to do with the same problem you have I paid 300 bucks for the boat its a bay liner 20 footer

  2. it's nice to have a good crew of friends to help out. I'm the same way I am blessed to have a good tight knit group of friends around to work on restoration projects.

  3. that engine is JUNK ,, your gonna  have to completely rebuild it ,,,I can guarantee you that ALL of the  bearings are  scored/pitted  including the  cam bearings 
    chances are   that heads are cracked or an intake possibly

  4. Roadking, that really looks like a mess. I really wasn't expecting to see the head gasket so thoroughly gone, as the exhaust manifolds are usually to blame for water in a marine engine. I have replaced a few head gaskets in 4.3 engines though. You should definitely have the heads surfaced. There will be staining or etching under the bad gasket areas if the leak has been present for very long. It is also possible that the gasket failure was caused by hydrolocking rather than being the initial water entry point. So check the manifolds. Freeze damage can also cause a crack in the bottom of the intake manifold. Those one piece exhaust manifolds are no longer available from Mercruiser. None of the aftermarket companies make a direct replacement either, as far as I know. The two piece manifold and elbow can be retrofitted. You asked whether that was called a manifold, or a riser? The answer is that the one piece is called a manifold. The top part of a two part exhaust system is called an elbow, or a riser, depending on whether it is a Mercruiser system, or a Volvo Penta system. Same thing, different nomenclature.
    After you get the engine back together, I would run it up to temperature, on the trailer, with water muffs over the water intakes, and then change the oil and filter again. Then if there is no new water in the engine, take the boat out and give it a good two hour run, and re check the oil. The heat will evaporate any remaining trace water. If you get new water in the engine, the exhaust manifolds are most likely to blame. 
    I spent 12.5 years as a marine mechanic, and/or service manager at boat dealerships in Sacramento, and Redding, California. I presently sell marine parts and accessories at Harbor Marine Maintenance and Supply in Everett, Washington.
    Good luck with the project. If you need any help or advice, let me know.
    Regards; Scott M.

  5. It looks like an old Buick V6 engine…They had an oil pump in the timing case here and EFI with electronic ignition (No Dizzy)…The screen on the oil pick up was tiny and the balance shaft bearing was always noisy and the cam bearings(only 3) would peal the center one out of the block and then the cam would snap in half.!…The heads used to crack quite a bit and the valve seats would hammer up in the head on the ones we had here in OZ.I've got the next carnation of that engine at work at the moment with bigger problems than a blown head gasket…lol

  6. Sure was a lot of ugly in that engine….  Sort of amazing that it cranked at all with all that water in the cylinders….  Looking forward to the next one….

  7. Few years ago a friend had a Sealine with a 350 small block Mercruiser. It dropped a valve seat insert. We think? it might have been converted to run unleaded, hence inserts. Quite by chance I met him on the first trip after the repair, done by another friend so not that expensive. Got a brilliant pic of me coming through the Glory Hole (High Bridge) in Lincoln……driving a £30grand boat and drinking REAL Champagne and I was wearing my very expensive Ferrari T shirt given to me by another good friend. Pics on FB if you can see it  https://www.facebook.com/photo.php?fbid=493208837375&set=a.446442967375.225653.634892375&type=3&theater

  8. It's definitely been run for a long time with water in the oil. I'd be putting new bearings in the bottom end too. I just had to put headgaskets in my 89 Chevy and I used diesel to clean everything good too. Those 4.3's are the same as a 350 just minus 2 cylinders except that's one of the newer ones with the balance shaft above the cam. They tend to crack heads pretty bad.

  9. Ahh the good ole 4.3 GM Mercruiser engine. I always preferred the 3.0 inline four in my boats. Keep up the videos, you always seem to have interesting projects.

  10. Wuter?  :o)  That looks a lot like the 4.3 litre i rebuilt in my daughter's 97 S-10 Blazer. yeah i thought so, hasn't been that long since i was rebuilding hers from the block up too.   Even if that timing chain wasn't loose i'd change that and the gears out both. yeah that gasket is GONE for it to be throwing that much water out and turned the oil like that , someone really gave that thing hell since the initial damage was done too.   They aren't that much. i bought a double roller gear set and chain with the new timing chain cover i think it was like $80.00 for all of it.  Yeah as thick as that sludge is all through the motor someone ran it like that for a while.  The sludge is brown because some of the brown from the rust mixed in the oil and water.  other wise it would just be gray or gray and white.  i know a guy that goes around to local shops when they pump gas out of a diesel tank when someone makes that mistake and gets what they pull out to clean his parts and things with.  they usually give it to him happily because other wise they have to pay to dump it somewhere and it's kinda expensive from what he tells me.  

  11. great coverage of the disassembly Roadking. with that much water/sludge in that engine it couldnt have had very good oil pressure, im wondering if the main and rod bearings are ok. sometimes that water/sludge with low oil pressure will compromise the bottom end. as far down as you have this, it may be worth pulling it out and checking the clearance of the bearings. anyway, great video my friend.

  12. Looks like all the oil passages need cleaned and check rod and mains.  I've seen water in engines but not like that.     Jay

  13. Looks like a Chevy 350ci. I've seen about 20 of these in the past month go through a buddy of mine's shop. If you come down to lloydminster AB they sell for cheap. As soon as I seen water I was like ' oh f+-k. Water in the cylinders means time for a new block.

  14. I would have taken the motor out.had a motor with the water pump on the end of the cam shaft so when the seal leaked water ran into the engine.A bad idea but also caused by me running the engine with out water going through it.We learn

  15. You guys are fucking up the man's carpet..you said yourself the tools were nasty and grimey yet they are threw all over the boat.

  16. looking for some advice. I know nothing about boats, a little experience with motors. Im looking to trade a rifle for a jon boat 16 footer with 70hp evinrude (with console and all that jazz). Older engine says it needs a tune up and what not, Whats the most it would cost to get an older outboard rebuilt and running good. what should i look for when i go to look at the boat? any help is appreciated thanks.

  17. 70hp is a big outboard but still a small engine, im guessing if i can work on motorcycles a some car stuff i can handle a boat motor, i just want to make sure i dont get stranded.

  18. Talk about hovering over someone when theyr'e working. He's making a youtube video! lol. Mechanic probably needs to go to the restroom.

Leave a Reply

Your email address will not be published. Required fields are marked *