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Tan, MerCruiser Certified Technician
Category: Boat
Satisfied Customers: 11073
Experience:  40 yrs. experience with complete engine repairs both inboard/outboard and MerCruiser Certified Technician.
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How to remove Mercruiser 454 Magnum from 1987 Sea Ray Sundancer.

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How to remove Mercruiser 454 Magnum from 1987 Sea Ray Sundancer. Motor is stuck, and rather than try to bust it loose and hope for the best I plan to open it up and rebuild it. 22+ years and 500 hours its probably due anyways. I found this forum ( for removing a 4.3 with a link to shop manual pages - was hoping something similar existed for the 454. Thanks in advance.
Is this a inboard eng. Disconnect wiring harness there should be a plug, disconnect control cables,unbolt shaft coupler, remove motor mount bolts not the nuts,disconnect exhaust hoses from risers, disconnect inlet water hose, disconnect fuel plug line be careful with fuel this is a fire hazard, lift eng out ,if stern drive same procedure except remove drive instead of shaft coupler. I will see if I can find that forum for you. Eng removal is same 4.3 or 454. If this helps click "Accept" button Thanks Tan

Edited by Tan Partin on 2/3/2010 at 6:57 PM EST
Customer: replied 7 years ago.
This is an I/O setup with an Alpha 1 outdrive. I understand most everything you said (fuel line, exhaust hoses, water hose, wiring harness), but where my knowedge from pickup trucks doesn't transfer is how to seperate the engine from the transmission/drive unit. Do I need to remove the outdrive at all? How does the engine connect/line up with the drive unit (bolts, splines, etc)?
At the back of the motor their is 2 motor mt bolts 3/4 socket and an extension. You can remove eng without pulling the drive but you have to remove the drive for installation. The drive has splined shaft that slides into eng coupler Just move eng forward don't lift eng to high. Thanks Tan
Customer: replied 7 years ago.
I will visually verify everything you said to do tonight when I get home. If you could, in the meantime, see if there is any shop manual or anything with illustrations on component locations, I would appreciate it.

Couple simple questions (I think) -
  • Once I pull the drive and engine, I have read that I will need a special "gimbal alignment tool" to reinstall. What is this tool, and where can I get one?
  • What is a rough estimate of time to free the engine to the point of lifiting it out? It doesn't seem like much (an hour or two), but this seems too easy and am wondering where the difficult step is that Im not accounting for

I think I have located a manual. An engine alignment tool you will have to borrow from a

Mercruiser Dealer. It roughly takes an hour, it is easy and there are no difficult steps.

Thanks, XXXXX XXXXX the accept button if this has been helpful.


Tan and other Boat Specialists are ready to help you
Customer: replied 7 years ago.
Thanks for the info. Send the manual my way and I'll accept your answer. P/N 90-144991 Mercruiser Service manual 1985-1988 This manual should give all the info. Thanks for your patience Tan