Logo
FULL SITE MENU

Crankshaft End Cap Bearings Spun

M

matthewharrison

Member
Hey,

I just acquired a Mercury Classic 40 - Oil injected, it's a 94 or somewhere around there 2 stroke 4 cylinder. I got the motor with a boat for free through family, but the boat had sunk with the motor on it a few years ago in salt water. They flushed it out from my understanding, but it was seized when we got it so I pulled it off the boat & stripped it down completely. The majority of it looks good, but I noticed a problem with the bearings on each end of the crank. They are a ball bearing and the crank is turning inside them, sometimes they get a little friction and the bearing spins, but most of the time the crank just spins inside the bearing.

I'm wondering if anyone can give me their opinion on the crank. I'm really hoping it's not hurt too bad because they're not cheap & I'm limited for money right now.

I've attached pictures of both ends (couldn't get uploader to work).
http://i.imgur.com/0ULiNSH.jpg
http://imgur.com/DwxJp96.jpg

Thanks guys.
 
Replace the lower bearing.---------The lower bearing just slips on the crankshaft and what you observed is normal.
 
???---------Just install new bearings and you are good to go.-------These bearings are a slip fit on the crankshaft.
 
racerone said:
???---------Just install new bearings and you are good to go.-------These bearings are a slip fit on the crankshaft.
Click to expand...

Awesome, glad to hear it.

Just out of curiosity, do you know the purpose of the slip fit? Does the crank expand to fit in it when it gets hot? I just like to know the purpose behind things I guess, haha.

Thanks for the answers & reply.
 
kimcrwbr1 said:
Put it together dry without the seals with just enough oil to keep stuff from rusting and check end play on the crank. I would replace both upper and lower bearings while you have it apart. You will find the new bearings will spin real easy.
Click to expand...

Yeah, I wanted to replace them anyway for peace of mind. I think I'm going to replace the needle bearings in the connecting rods as well.
 
Unless there's signs of rusting on the rod joints--which means the crank is scrap-then that's not necessary.


Jeff
 
Really? IF there are no rusty indentations you can feel with your fingernail, you might be able to reuse the rods (and crank). If there is, though, they are scrap!

Fired up an old KG-7 the other day that had (unbeknownst to me) such parts--and it ate a rod.

Jeff
 
Back
Top