Time to replace crankshaft bearing?

[nzahradka]

1986 75 hp Mercury 4 cyl S/N 0A198913

The old Mercury stator failed low side resistance and voltage tests. High side tests fine. There is evidence of the flywheel rubbing the stator (pics attached), and there is some play in the upper crankshaft bearing. Compression is 120 lbs on all 4 cylinders.

http://www.youtube.com/watch?v=4b4rMIEvse4

I have a new CDI stator, but I'm waiting to install because I don't want to destroy the new one.

Is replacement of the upper crankshaft bearing a must at this point? And I'm assuming I have to split the crankcase to do so?

 

[Texasmark]

Re: Time to replace crankshaft bearing?

I think you nailed it. If you can grasp the top of the crank and cause any lateral movement you are ready for some new bearings.

Mark

 

[chum1]

Re: Time to replace crankshaft bearing?

good description and vid., if it were me i would explore ways to just pull the top bearing and replace, install new seal, and enjoy whats left of the summer

 

[zorak]

Re: Time to replace crankshaft bearing?

That is a ball bearing i think.If its loose then it could possibly fly apart on you which of course would grenade your block.AS far as pulling it out without block dissasembly i would wait to see if someone more knowledgeble than me will chime in on this one.I don't know if the bearing is pressed to the crank but i don't think your gonna get lucky enough to get it out w/o splitting the block.I think the risk of damage is too great to attempt it.Of course if an expert on this forum says it can be be removed then there might be some sort of puller you can buy or you could tack weld something to the bearing to aid in removal,you would just have to make sure the crankshaft surfaces are shielded from any splatter and you don't put too much heat to it.