Engine removal with boat in the water

[Dmerg]

Hello, I have a 1991 Baja 340 motor yacht with twin carbureted 7.4L mercruiser engines with Bravo 1 out drives. Over the summer I replaced the starter on my port engine with a reman starter and one morning I attempted to start my port engine but the battery was dead. I jumped the dead battery with my starboard battery and found the reman starter failed in the engaged and spinning mode without the key being turned. Long story short, my flywheel now has some bad spots and needs to be replaced. I keep my boat in a boat garage and I have large overhead beams that I can use as a hoisting point. After reading other posts it sounds like I can move the engine without removing the outdrive. I noticed the motor mounts are bolted to large L brackets that are through bolted to the stringers. It is my understanding that I just need to move the engine 1 foot forward to be able to get to the flywheel. Here are my questions:
1. is my plan to move the engine while the boat is in the water doable?
2. can I just remove the motor mount brackets from the stringers instead of removing the motor mount top nuts? My thinking is that this approach wont require me to lift the engine vertically more than a few inches so I can slide it forward off of the stern drive shaft.
3. If I make witness marks for the motor mounts brackets will that be good enough for engine/driveshaft alignment until the boat is hauled and I can pull the drive for winter storage? (The marina I winter store doesn’t allow major mechanical work while in storage but I can at least pull the drive)
i appreciate any input, Dave

 

[Scott06]

No not doable while theoretically you can move the engine forward you will not be able to line up the drive shaft and coupler reinstalling the engine. Nor check alignment of engine
haul the boat pull the drives and yank the engines

 

[Rick Stephens]

⇧ ⇧

 

[Scott Danforth]

you have to remove the drive to pull the shaft out of the motors bung-hole

you have to have the drive off to re-install the motor and align the motor

no amount of witness marks are going to help you

pull the boat, get it on the hard, then pull the drives and then pull the motors

you dont need a new flywheel, you need a new $14 ring gear for your flywheel.

 

[Dmerg]

you have to remove the drive to pull the shaft out of the motors bung-hole

you have to have the drive off to re-install the motor and align the motor

no amount of witness marks are going to help you

pull the boat, get it on the hard, then pull the drives and then pull the motors

you dont need a new flywheel, you need a new $14 ring gear for your flywheel.

Thanks guys for fast responses. I learned the hard way with a reman starter vs a mercruiser starter which I now have. The reman shop said they didnt understand what happened but it likely happened overnight and I didn’t hear the starter cranking away turning the engine until the voltage dropped enough where the bendix no longer would hold in the flywheel gear but enough to grind away at the teeth. Murphys Law

 

[Rick Stephens]

There actually isn't any such thing as a 'Mercruiser' starter. Merc don't make em. But your point is valid. Quality matters back there when a miss costs so much. Best of luck on your repair.

Rick

 

[Scott Danforth]

the "Mercruiser" starter is an AC Delco that is shipped on the motor from GM

there is also Argo and a prestolite that were used over the years.

 

[Dmerg]

There actually isn't any such thing as a 'Mercruiser' starter. Merc don't make em. But your point is valid. Quality matters back there when a miss costs so much. Best of luck on your repair.

Rick

I appreciate the well wishes. i looked at the box for the starter, you were right, its not Mercury, but rather Quicksilver.

 

[Rick Stephens]

I appreciate the well wishes. i looked at the box for the starter, you were right, its not Mercury, but rather Quicksilver.

Quicksilver is the name that Merc slaps on stuff they license or make themselves. In this case, that is almost 99.9% certain to be an ACDelco starter made for GM and repackaged by Merc for you. I am usually fairly loath to purchase stuff from Merc, made for Merc, by standard automotive sources. I do buy rubber parts from them. Sometimes a lubrication product.

 

[Scott06]

Quicksilver is the name that Merc slaps on stuff they license or make themselves....I do buy rubber parts from them. Sometimes a lubrication product.

The difference between Mercury labeled parts and Quicksilver labelled parts Is where they are sold. Merc labels parts/ lubes are sold through their dealer network, where quicksilver is Allowed to be sold outside their dealer network. Often the part numbers are the same with the exception of a Q in there otherwise basically the same PN,

I would second the rubber parts like bellows and impellers are wroth the money, I also get the quicksilver hi perfgear lube at Wally World cause it’s only $11/ qt there vs like $20 at Bass Pro.

 

[Dmerg]

The difference between Mercury labeled parts and Quicksilver labelled parts Is where they are sold. Merc labels parts/ lubes are sold through their dealer network, where quicksilver is Allowed to be sold outside their dealer network. Often the part numbers are the same with the exception of a Q in there otherwise basically the same PN,

I would second the rubber parts like bellows and impellers are wroth the money, I also get the quicksilver hi perfgear lube at Wally World cause it’s only $11/ qt there vs like $20 at Bass Pro.

Scott and Rick, I do appreciate your insight and your time to reply to my questions. I want to preface my response below to say that I do not intend to offend or diminish your input. Prior to posting this question, I spoke to the marine mechanic at the marina up the street from whom I often get parts from and also tips/tricks/lessons learned when working on my boat. I consider myself to be an advanced DIYer and also a frugal person, an engineer who likes the challenges of DIY. I asked the mechanic if its possible to replace the flywheel ringgear while the boat is floating, and he said yes. He is familiar with my boathouse and the structure to perform the lift. He didn’t mention any gotcha’s of my plan or sway me otherwise even though my alternate plan is for him to do the work for $1000 once the boat is pulled and I remove the wrap around seating and large flooring panel over the engines. Also, I inquired with my old neighbor who comes from a family of performance boat racers and he told me that it is possible as well, and the only additional advice he offered is to lighten the load by removing the exhaust manifolds. So my question to you guys is: Have you tried to do what I am planning and struggled or know someone who tried and failed miserably? Again, I appreciate your time.

 

[Rick Stephens]

Seems you already found the answer you were looking for.

I'd hate to try it with a 4.3L. Can't imagine the smoke coming out the ears with a 7.4L. And note, when all finished, impossible to know if you have alignment. But can do it all over again and replace the coupler. Easy peasy, right?

 

[Bt Doctur]

Without perfect alignment a coupler is destroyed in as little as 15 hours. Knowing you have to lift the rear of the engine to remove it, how is that done if connected to the coupler? If your mechanic worked on race boats he would have told you that most use jackshafts from engine to drive .With those you can pull the engine .
If you do go with this mechanic get it in writing that he will pull the engine and replace the coupler for free when it goes bad.

 

[Dmerg]

Without perfect alignment a coupler is destroyed in as little as 15 hours. Knowing you have to lift the rear of the engine to remove it, how is that done if connected to the coupler? If your mechanic worked on race boats he would have told you that most use jackshafts from engine to drive .With those you can pull the engine .
If you do go with this mechanic get it in writing that he will pull the engine and replace the coupler for free when it goes bad.

So after considering the input you guys have provided. I plan to winter store my boat at the mechanics marina that way I am already in line for the repair in the spring along with eliminating an extra $200 hoist fee if I stored at my usual marina. So the cost for the repair is now $800 instead of $1000 and the repair will be done while dry docked with the stern drive removed. It took some time to get through to me. Thanks again guys

 

[Scott Danforth]

an engineer who likes the challenges of DIY.

caution, you may have opened yourself up to ridicule for that.....

BTW, many of us are engineers....... And I have the picture of me driving the train to prove it..... LOL

going off experience as well as personally knowing the engineers at Volvo, Mercruiser, PCM, Indmar, Ilmor, etc. as well as most of the testing staff at Mercuiser (even the defunct Stillwater plant).......while you can technically pull the motor forward and wrestle the flywheel off, pull it onto your bench, knock off the ring gear and then reverse the process while the boat is still in the water.......... doesnt mean you should.

there is no way to ensure alignment short of pulling the drive and greasing up the alignment tool (which not only ensures alignment, it also magically greases the splines of the coupler). you will literally fight for hours to get the splines lined up vs simply pulling the drive.

as BT mentioned, most Sausage boats use jack shafts and offset boxes. you can pull that in a heart beat because the flywheel housing stays on the motor and the jackshaft is bolted to the stub (no alignment needed)

 

[Rick Stephens]

A favored engineer story. An software engineer walks into his office pushing a bike. His fellow engineer asks where he got it. He explains as he walked in from the parking lot a beautiful girl rode up, jumped off the bike, tore off her clothes and posturing, said, 'take whatever you want'. The other engineer replied, 'good choice, the clothes probably wouldn't have fit'.

 

[Dmerg]

A favored engineer story. An software engineer walks into his office pushing a bike. His fellow engineer asks where he got it. He explains as he walked in from the parking lot a beautiful girl rode up, jumped off the bike, tore off her clothes and posturing, said, 'take whatever you want'. The other engineer replied, 'good choice, the clothes probably wouldn't have fit'.

Thanks guys for the friendly ribbing as I opened myself up to it. By the way i am a software engineer and plan to share that joke with my fellow engineers.