4.3 mercruiser rebuild

[WetJunky]

Hello all,

As you can see, I am new here. I am new to boating, not mechanics. About a month ago, I bought a 1997 Maxum bowrider with the 4.3... I got a deal because the trailer was in serious need of love. I spent the last month repairing the trailer, installing new bilge pump, and replacing the impeller before launching her for my first time yesterday.

5 minutes out, she died. No fuel. Tracked around and found a wire undone due to a broken clip on the plug... Fixed.

Ran great all day.

Launched her today in a lake, ran her hard for about an hour... buzzer came on, low oil pressure. shut her down. Open the engine compartment to find oil in the bottom...

tracked the leak to what I think is a oil pressure sending unit... (no big deal) Got her back in the driveway and topped off the oil... started her up with the muffs... :facepalm:

I am new to boating... not motors... Sounds like a rod knock in the bottom end and ticking from the valve covers that sounds like lifters or something in the valve train.

Everyone warned me... I knew it was coming. just hoped for a little bit more fun before something serious like pulling the motor.

So... That's me... That rookie you all have probably towed back to the boat launch before. I have searched through your forum and already found some people who sound like they have/had similar problems.

I intend to post updates and pics of all steps in my progression. This will not be that fast due to the fact that I work full time, college part time, and I have 50% custody of my almost 3 year old daughter.

I have 2 weeks before I can pull the motor and tear her apart.

Questions...

What is the best way to pull the motor?.. a standard cherry picker does not appear to cut it, and I would really rather refrain from showing my redneck tendencies to the neighbors by using a come-along and the oak tree in the front yard. Although, I will if needed.

Is there any good write ups or videos for pulling a motor out of a boat?

What else should I dig into or inspect while I am in there? Remember, not new to motors, very new to boats.

Thanks in advance for any useful information given.

Here we go

 

[saltlydawg]

Re: 4.3 mercruiser rebuild

Hey I am no red neck, but i used the oak tree approach to remove mine for rebuild. My approach to reinstall it is renting time on an overheard Gantry style crane. You might call your local rental place to see about renting an Ibeam with a winch. The 4.3 I believe weighs in around 875 lbs with all the accessories. Removing the exhaust lightens the load.

Good luck and you might want to look at a rebuilt engine. I just did my own rebuild and the total difference between getting a rebuilt one delivered and doing my own rebuild was about $400.00. This is based on Rapido Marine verses my local machine shop.

 

[WetJunky]

Re: 4.3 mercruiser rebuild

Thanks. I will wait until i tear it down to see how bad a spun it up, but I am already shopping new blocks. I was also looking at Rapido. My local rental shop says they have just what i need. An engine hoist that sits on a trailer. "Great for pulling inboard and outboard motors." I think the called it a tip toe engine hoist.

 

[firecapt13]

Re: 4.3 mercruiser rebuild

If the block is good I would rebuild the one you have. You can get automotive parts and replace. I called Mercruiser and verified that the internals are the same as auto applications. I used the overhead door header beam and come along to pull my engine.

 

[340]

Re: 4.3 mercruiser rebuild

I bought a 1998 23' Trophy with a bad crank (4.3). on initial inspection I found a rust hole in the oil filter, all engine oil was in sump. the engine had allready been removed when I got the boat. I tore the engine down to the bare block and found the cylinders, pistons, rings, heads all good, factory hone marks still visible, no skuff's. with engine on stand I removed all galley and freeze plugs, washed and cleaned all oil galleys with cordless drill and galley brushes, re-assembled short block with original pistons, had 1 rod reconditioned, crank kit, cam brgs, new oil pump and lifters. I will use my kubota tractor with frt bucket and boom to re-install, problem is, the flywheel and coupler is missing. I found a flywheel (according to the starter bolts it uses a 14'' flywheel)but don't know which coupler to use on the alpha 1 outdrive.

 

[MSRTBUDWISER]

Re: 4.3 mercruiser rebuild

Hey there...

I'm in just about the same "boat" as you here. I just bought a 2001 Maxum 1800 with the 4.3. Similar thing happened to me, first trip out, about 2 minutes away from the dock, the motor developed a loud "knock". I was told that it might have been the gimbal bearing (bs because they growl, don't knock) or that it might have been a stuck lifter (but this wasn't a "tick" it was a definite "knock"). Well to cut a long story short, if you have a 1800 or 1900, then a "cherry picker" with a extendable boom will work great. I just used one yesterday to pull mine. It cleared the back of the boat with about 4-5 inches to spare. Also, I didn't pull the outdrive, I just unbolted the motor mounts from the block, so that I don't have to re-align it when putting it back in. The mechanic pulled it apart in front of me and it was a spun rod bearing. Hes using a re-machined crank, total cost is around $950. I hope this helps... Let me know if you have any other questions since I just pulled mine yesterday! Happy Boating!