Broken Bolts on flywheel

[nkswell]

Motor was running great. Had engine wide open for a few minutes. Heard a slight change in the sound of engine. Brought it back to the dock. Heard a rattle or knock when I turned it off. Tried to restart engine but would not start. But when it attempted to turn I heard knocking and clanging. I found that most of the bolts on the flywheel had broke off. Have NO idea how this happened. I plan to pull the engine to see what I am up against. Hopefully just replacing the bolts. The main concern I have is could this have caused internal problems. Has anyone seen this happen and if so what was the outcome? Thanks
1987 Mercruiser 165 3.7

 

[MikDee]

Never heard of this? Maybe they were the wrong strength bolts!? Material too soft.

 

[alldodge]

Agree with MikDee, never heard of it and will add; I don't see anything happening to the internals of the engine. My guess is someone overhauled the engine and either didn't torque and loctite the bolts, or misplaced them and use incorrect grade

 

[Bt Doctur]

Me too, wrong grade bolt, wrong bolt, not fastened correctly

 

[Bondo]

Ayuh,.... Their Studs, not bolts ain't they,..??

 

[Bt Doctur]

Studs in most cases, atleast from the factory. might have had a flywheel conversion to a triangular coupler. If they were bolts you would find the heads in the bilge if they escaped the dust cover or the nut with a portion of the threaded stud

 

[nkswell]

Pulled engine. Nothing broken. The studs with the nuts attached came out. No sign of loktite on the stud. Put the studs back in with loctite on it. Engine is back in all I need to do is hook it up and start it.