Caged connecting rod bearings........

[mechanicsgal]

Does anyone know if they had problems in old Mercs with the caged bearings? I posted down further and no one knew the answer as to why 3 out of 4 of our bearings have broken. We were at full throttle....heard a "clunk", engine lost power and when taken apart....one piston smoked and bearings broken. Not sure if RPM's were off and motor ran too hard or what...

 

[mechanicsgal]

Re: Caged connecting rod bearings........

Forgot to mention......our motor is a 1971 Mercury 80 hp.....serial 3053642.....Thunderbolt ignition. Thanks.

 

[steelespike]

Re: Caged connecting rod bearings........

I cirtainly wouldnt be surprised at a 31 year old motor having bearings fail.If it was babied all its life and had low hours then I would wonder<br />a little bit.But lets face it an outboard works hard.Some run day after day wot max rpm and hold together for years.Then add in the folks that forget the oil or skimp on oil::<br /> Boom!

 

[mechanicsgal]

Re: Caged connecting rod bearings........

Thanks a lot for the info.....we were wondering if maybe the bearings just failed and we have to replace them and the piston. We're crossing our fingers that that is the problem.....thanks for your input!!!!!<br /><br />Aimee

 

[HowieDean]

Re: Caged connecting rod bearings........

Caged roller bearings have a tendency to strech after a few years... 3 failing at the same time is not a good sign... Something else happened...<br />You say you smoked.. a pistion.. Are we talking dry and pitted... or just broken... did any off the needles go through the motor ????? Be sure when you rebuild it to also rebuild the carbs and check everything out.... 3 out of 4 bearings did not fail from fatigue.... Something went wrong with fuel delivery... timing... oil mix... find out what caused the failure... or you will just blow it up again....