Bought a replacement Merc 3.0 Engine - wrong flywheel/coupler

[islandboy47]

My Mercruiser 3.0 motor bit the dust so I bought a rebuilt one from a mechanic online. The motor is all well and good, but when looking into putting into the boat we realized the "new" motor came with a different sized flywheel and doesn't fit the coupler I currently have. After doing some Googling now I realize there were two different versions of this motor where they changed the flywheel size and coupler set up. Now I'm totally confused about what to do - I know I have to use a different starter than what I currently have (the reman engine has the straight bolts for the starter, not staggered) but I have no clue how to address the issue regarding attaching the flywheel/motor to the outdrive. Obviously I wish I had done more research and known about this compatibility issue beforehand, but here I am. Has anyone here successfully remedied a situation like this?

 

[alldodge]

Yep ya bought a older 3.0
Hey @Bondo could use your advise

 

[kenny nunez]

If the bolt circle on the replacement engine is larger than the previous engine then you will need the following from Sierra Marine. 877 663 8396
18-72510 stud kit
18-2171 Coupler.
Double check with them but this should get you back in the water.

 

[Bondo]

Yep ya bought a older 3.0
Hey @Bondo could use your advise

Ayuh,...... Welcome Aboard islandboy,...... Sierra sells an adapter type crankshaft mounted coupler, with the right bolt pattern for that motor,.....
I don't have a part number, but it should be an easy search,......

With only the straight pattern starter, ya gotta use the small flywheel,....

edit: thank you kenny,..... that one,.....

 

[islandboy47]

Thank you guys! After posting this I found that coupler online and thought maybe that's what I need. I never would have known to get the stud kit.